СТАЛЬНЫЕ ЛИСТЫ ДЛЯ СВЕРХВЫСОКОПРОЧНЫХ МАГИСТРАЛЬНЫХ ТРУБ И СВЕРХВЫСОКОПРОЧНЫЕ МАГИСТРАЛЬНЫЕ ТРУБЫ, ОБЛАДАЮЩИЕ ПРЕКРАСНОЙ НИЗКОТЕМПЕРАТУРНОЙ УДАРНОЙ ВЯЗКОСТЬЮ, И СПОСОБЫ ИХ ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, в частности к производству стального листа для изготовления сверхвысокопрочных магистральных труб, обладающих прекрасной низкотемпературной ударной вязкостью. Техническим результатом изобретения является обеспечение прочности на тангенциальное растяжение не ниже 900 МПа, не увеличивая при этом прочность на осевое растяжение труб, производимых путем шовной сварки краев листов. Для достижения технического результата листы получают из стали, содержащей, мас.%: С от 0,03 до 0,07, Si не более 0,6, Mn от 1,5 до 2,5, Р не более 0,015, S не более 0,003, Ni от 0,1 до 1,5, Мо от 0,15 до 0,60, Nb от 0,01 до 0,10, Ti от 0,005 до 0,030, Al не более 0,06, один или более элементов из группы: В, N, V, Cu, Cr, Ca, РЗМ и Mg в необходимых количествах, остальное железо и неизбежные примеси, лист имеет отношение (Hv-avep)/(Hv-M*): средней твердости Hv-avep по Виккерсу в направлении толщины к твердости мартенсита - Hv-M*, определяемой содержанием углерода, составляющее ...

ЛИСТ ДВУХФАЗНОЙ СТАЛИ И СПОСОБ ЕГО ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии. Для повышения пластичности и прочности с обеспечением равномерного относительного удлинения и пригодности для отбортовки отверстий получают лист из двухфазной стали, содержащей, мас. %, C 0,01-0,1, Mn 0,2-3, Al 0,04-1,5, Ti 0,015-0,2, P 0,01 или менее, S 0,005 или менее, N 0,01 или менее, при выполнении условия [Ti] - 48/14 × [N] - 48/32 × [S] ≥ 0%, и когда установлено Ex.C (%) = [C] - 12/48 × {[Ti]+48/93 × [Nb] - 48/14 × [N] - 48/32 × [S]}, то выполняется условие 0,001 ≤ Ex.C (%)/fsd (%) ≤ 0,01, Fe и примесей остальное, при этом на глубине 1/4 толщины листа микроструктура является двухфазной, с ее основной фазой, состоящей из полигонального феррита, дисперсионно упрочненного карбидом Ti, и ее второй фазой, состоящей на 1-10% по доле площади (fsd (%)) из множественно диспергированных продуктов низкотемпературного превращения, и средний диаметр кристаллов продуктов низкотемпературного превращения составляет 3-15 мкм, и среднее значение расстояния ...

ТРАВЛЕНИЕ НЕРЖАВЕЮЩЕЙ СТАЛИ В ОКИСЛИТЕЛЬНОЙ ЭЛЕКТРОЛИТИЧЕСКОЙ ВАННЕ С КИСЛОТОЙ

Изобретение относится к электролитическим способам обработки металлов и может быть использовано для травления полосы из нержавеющей стали. Способ включает травление полосы из нержавеющей ферритной стали в ванне смесью, содержащей HSOи избыток по меньшей мере одного окислителя, при этом на сталь подают электрический ток, а указанная смесь не содержит HF. Второй вариант способа включает обработку указанной стали в ванне смесью, содержащей HSOи избыток по меньшей мере одного окислителя, обеспечивающего превращение всего количества сульфата железа (II) в сульфат железа (III) (Fe(SO)), и подачу тока на сталь, причем концентрация HSOсоставляет от 10 г/л до 200 г/л. Технический результат: снижение общего количества химических реагентов, содержащихся в электролите травления. 2 н. и 23 з.п. ф-лы, 6 табл., 4 пр., 3 ил.

СТАЛЬНОЙ ЛИСТ ДЛЯ ГОРЯЧЕЙ ШТАМПОВКИ И СПОСОБ ИЗГОТОВЛЕНИЯ ДЕТАЛИ ИЗ СТАЛЬНОГО ЛИСТА ГОРЯЧЕЙ ШТАМПОВКОЙ

Изобретение относится к стальным листам для горячей штамповки, которые могут быть использованы для производства деталей, в частности деталей шасси транспортных средств, деталей подвески и конструктивных элементов кузова, а также к способам производства деталей из стальных листов горячей штамповкой. Стальной лист для горячей штамповки содержит слой покрытия, содержащий 10-25 мас.% Ni, Zn и неизбежные примеси - остальное, и имеющий массу на единицу площади 10-90 г/м, и смазывающий слой, содержащий твердый смазывающий материал, нанесенные в указанном порядке на поверхности стального листа. Способ производства детали горячей штамповкой включает холодную штамповку упомянутого стального листа для горячей штамповки с последующим нагревом стали, подвергнутой холодной штамповке, до температуры в диапазоне температуры фазового превращения Асдо 1000°C и горячую штамповку стали. Обеспечивается стальной лист для горячей штамповки, имеющий улучшенную стойкость против окисления, способность к сдерживанию ...

СПОСОБ ИЗГОТОВЛЕНИЯ СТАЛЬНОЙ ДЕТАЛИ

Изобретение относится к области металлургии, а именно к изготовлению стальной детали из стального листа. Стальной лист имеет состав, включающий в мас.%: С: 0,05-0,25, Mn: 3,5-8, Si: 0,1-2, Аl: 0,01-3, S ≤ 0,010, Р ≤ 0,020, N ≤ 0,008, при необходимости Cr: 0-0,5 и/или Mo: 0-0,25, остальное - железо и неизбежные примеси. Лист имеет микроструктуру, включающую, в долях поверхности, 10-50% остаточного аустенита, 50% или более суммы феррита, бейнита и отпущенного мартенсита, менее 5% свежего мартенсита и менее 2% карбидов. Содержание углерода [C]A в аустените строго более 0,4 и строго менее 0,7 мас.%, а массовый процент азота %N, кремния %Si, марганца %Mn, хрома %Cr, никеля %Ni, меди %Cu, молибдена %Mo и углерода в аустените [C]A, такие, что Md30 находится в диапазоне 200-350°C, причем Md30 определяется как: Md30(°C) = 551 - 462*([C]A +%N) - 9,2*%Si - 8,1*%Mn - 13,7*%Cr - 29*(%Ni+%Cu) - 18,5*(%Mo). Указанный стальной лист разрезают до заданной формы для получения стальной заготовки. Стальную ...

ЛИСТОВАЯ ФЕРРИТНАЯ НЕРЖАВЕЮЩАЯ СТАЛЬ, СПОСОБ ЕЕ ПРОИЗВОДСТВА И ЕЕ ПРИМЕНЕНИЕ, ОСОБЕННО В ВЫХЛОПНЫХ СИСТЕМАХ

Изобретение относится к области металлургии, а именно к листовой ферритной нержавеющей стали, использующейся для производства деталей, подверженных действию высоких температур, в частности элементов выхлопных систем двигателей внутреннего сгорания. Сталь содержит, мас.%: следовые количества ≤C≤0,03, 0,2≤Mn≤1, 0,2≤Si≤1, следовые количества ≤S≤0,01, следовые количества ≤P≤0,04, 15≤Cr≤22, следовые количества ≤Ni≤0,5, следовые количества ≤Mo≤2, следовые количества ≤Cu≤0,5, 0,160≤Ti≤1, 0,02≤Al≤1, 0,2≤Nb≤1, следовые количества ≤V≤0,2, 0,009≤N≤0,03, следовые количества ≤Co≤0,2, следовые количества ≤Sn≤0,05, редкоземельные элементы (РЗЭ) ≤0,1, следовые количества ≤Zr≤0,01, остальное железо и неизбежные примеси. Содержания Al и редкоземельных элементов (РЗЭ) удовлетворяют зависимости Al+30×РЗЭ≥0,15%, а содержания Nb, C, N и Ti в % удовлетворяют зависимости 1/[Nb+(7/4)×Ti-7×(С+Ν)]≤3. Лист имеет полностью рекристаллизованную структуру и средний размер ферритного зерна между 25 и 65 мкм. Достигается ...

СТАЛЬ, ПРОДУКТ, ПРОИЗВЕДЕННЫЙ ИЗ ТАКОЙ СТАЛИ, И СПОСОБ ЕГО ИЗГОТОВЛЕНИЯ

Сталь, характеризующаяся тем, что ее состав, мас. %, представляет собой: 10,0≤Ni≤24,5; 1,0≤Mo≤12,0; 1,0≤Со≤25,0; 20,0≤Мо+Со+Si+Mn+Cu+W+V+Nb+Zr+Ta+Cr+C≤29,0; Со+Мо≥20,0; Ni+Co+Mo≥29; следовые количества≤Al≤4,0; следовые количества≤Ti≤0,1; следовые количества≤N≤0,0050; следовые количества≤Si≤2,0; следовые количества≤Mn≤4,0; следовые количества≤C≤0,03; следовые количества≤S≤0,0020; следовые количества≤Р≤0,005; следовые количества≤В≤0,01; следовые количества≤Н≤0,0005; следовые количества≤О≤0,0025; следовые количества≤Cr≤5,0; следовые количества≤Cu≤2,0; следовые количества≤W≤4,0; следовые количества≤Zr≤4,0; следовые количества≤Ca≤0,1; следовые количества≤Mg≤0,1; следовые количества≤Nb≤4,0; следовые количества≤V≤4,0; следовые количества≤Ta≤4,0; остаток - железо и неизбежные примеси. Техническим результатом является изготовление стали с улучшенными механическими свойствами. 8 н. и 27 з.п. ф-лы, 3 ил., 7 табл.

ЛИСТ ИЗ СОДЕРЖАЩЕЙ Nb ФЕРРИТНОЙ НЕРЖАВЕЮЩЕЙ СТАЛИ И СПОСОБ ЕГО ПРОИЗВОДСТВА

Изобретение относится к области металлургии, а именно к горячекатаному стальному листу из ферритной нержавеющей стали, подвергаемому отжигу и холодной прокатке. Лист имеет химический состав, содержащий, мас.%: от 0,004 до 0,030% C, 1,50% или меньше Si, 1,50% или меньше Mn, 0,040% или меньше P, 0,010% или меньше S, от 12,0 до 25,0% Cr, от 0,005 до 0,025% N, от 0,20 до 0,80% Nb, 0,10% или меньше Al, от 0 до 3,0% Mo, от 0 до 2,0% Cu, от 0 до 2,0% Ni, от 0 до 0,30% Ti, от 0 до 0,0030% B, остальное - Fe и неизбежные примеси. Количество в листе выделений, содержащих Nb, составляет 0,20 мас.% или более, а средний диаметр частиц указанных выделений составляет от 2,0 до 10,0 мкм применительно к диаметру эквивалентной окружности. Лист обладает требуемой обрабатываемостью и высокой стойкостью к образованию вмятин. 4 н. и 1 з.п. ф-лы, 1 ил., 2 табл.

СПОСОБ ИЗГОТОВЛЕНИЯ ДЕТАЛИ ПУТЕМ ГОРЯЧЕЙ ДЕФОРМАЦИИ СТАЛЬНОЙ ЗАГОТОВКИ

Изобретение относится к области металлургии, а именно к способу изготовления детали, имеющей бейнитную микроструктуру с минимальной прочностью на разрыв 800 МПа и используемой в автомобильной промышленности. Способ включает нагрев по меньшей мере части стальной заготовки до температуры горячей деформации и ее деформацию. Указанная заготовка изготовлена из стали, имеющей микроструктуру, содержащую по меньшей мере 50% бейнита, а нагрев по меньшей мере части заготовки осуществляют до температуры ниже температуры превращения Ас. Заготовка изготовлена из стали, имеющей следующий состав, мас.%: С: 0,02-0,3, Si: 0,01-0,5, Mn: 1,0-3,0, P: макс. 0,02, S: макс. 0,01, N: макс. 0,01, Al: до 0,1, Cu: до 0,2, Cr: до 3,0, Ni: до 0,2, Mo: до 0,2, Ti: до 0,2, V: до 0,2, Nb: до 0,1, B: до 0,01, Fe - остальное. Обеспечиваются требуемые механические свойства. 14 з.п. ф-лы, 2 табл.

СПОСОБ И УСТАНОВКА ДЛЯ ИЗГОТОВЛЕНИЯ ГОРЯЧЕКАТАНОЙПОЛОСЫ ИЗ АУСТЕНИТНЫХ НЕРЖАВЕЮЩИХ СТАЛЕЙ

Изобретение относится к области горячей прокатки. Задача изобретения - повышение эффективности изготовления катаных продуктов из аустенитных нержавеющих сталей. На первом этапе литую заготовку подвергают процессу прокатки в прокатном стане с чистовой линией, а на втором этапе осуществляют термообработку для предотвращения подверженности коррозии, в частности, в отношении межкристаллитной коррозии из-за выделений карбидов хрома. Для установления определенной конечной температуры прокатки температуру перед чистовой линией устанавлявают выше 1150°С, предпочтительно выше 1200°С. Нагревают по меньшей мере в две ступени. Термообработку проводят с прокатного нагрева. Кроме того, предложена соответствующая установка, содержащая средства подогрева и интенсивного нагрева до указанной температуры литой заготовки перед чистовой линией прокатки и средства термообработки с прокатного нагрева. Изобретение обеспечивает возможность экономии энергии и времени при производстве аустенитных нержавеющих сталей ...

МАРТЕНСИТНО-ФЕРРИТНАЯ НЕРЖАВЕЮЩАЯ СТАЛЬ, ИЗГОТОВЛЕННЫЙ ПРОДУКТ И СПОСОБЫ ИХ ПРИМЕНЕНИЯ

Изобретение относится к мартенситно-ферритной нержавеющей стали с высокой коррозионной стойкостью, готовому продукту и к способам изготовления штампованных или прокатных продуктов или сортового проката и бесшовных труб из мартенситно-ферритной нержавеющей стали. Сталь имеет мартенситно-ферритную структуру и химический состав, в вес.%: С от 0,005 до 0,030, Si от 0,10 до 0,40, Mn от 0,20 до 0,80, Р максимум 0,020, S максимум 0,005, Cr от 13 до 15, Ni от 4,0 до 6,0, Мо от 2,0 до 4,5, V от 0,01 до 0,10, Nb от 0,01 до 0,50, N от 0,001 до 0,070, Al от 0,001 до 0,060, Ti от 0,001 до 0,050, Cu от 0,01 до 1,50, B ниже 0,01, О максимум 0,005, остальное - Fe и неизбежные примеси, обусловленные промышленной обработкой. Сталь имеет параметр локальной коррозии (LCP) от 3,2 до 6,2, определённый уравнением: LCP = 0,500×%Cr + 1,287×%Мо + 1,308×%N - 5,984. В способах изготовления готовых продуктов температура нагрева на заданном этапе удовлетворяет уравнению: T - 16,9×%Cr - 49,9×%Мо>535. Технический результат ...

ГОРЯЧЕФОРМОВАННЫЙ ЭЛЕМЕНТ И СПОСОБ ЕГО ИЗГОТОВЛЕНИЯ

Изобретение относится к области машиностроения. Для повышения пластичности элемента базовый стальной лист, содержащий, мас.%: С 0,05-0,40, Si 0,5-3,0, Mn 2,4-8,0, Р 0,05 или менее, S 0,01 или менее, раств.Al 0,001-2,0, N 0,01 или менее, Ti 0-1,0, Nb 0-1,0, V 0-1,0, Cr 0-1,0, Мо 0-1,0, Cu 0-1,0, Ni 0-1,0, Са 0-0,01, Mg 0-0,01,РЗМ 0-0,01, Zr 0-0,01, В 0-0,01, Bi 0-0,01, Fe и примеси - остальное, имеющий микроструктуру с общей относительной площадью бейнита и/или мартенсита более или равной 70% площади, и частицы цементита с плотностью, более или равной 1,0 частиц на мкм, нагревают до температуры более или равной 670°С и менее 780°С, которая менее температуры Ас, выдерживают в упомянутой области в течение 2-20 минут, формуют в горячем состоянии и охлаждают со средней скоростью охлаждения от 5 до 500°С/с в области температур 600-150°С с получением горячеформованного элемента, имеющего микроструктуру с содержанием аустенита с относительной площадью от 10 до 40% площади, при которой общая численная ...

СПОСОБ ПРОИЗВОДСТВА АУСТЕНИТНЫХ ЖЕЛЕЗОУГЛЕРОДМАРГАНЦЕВЫХ СТАЛЬНЫХ ЛИСТОВ, ИМЕЮЩИХ ОЧЕНЬ ВЫСОКУЮ ПРОЧНОСТЬ И ХАРАКТЕРИСТИКИ УДЛИНЕНИЯ, А ТАКЖЕ ИСКЛЮЧИТЕЛЬНУЮ ОДНОРОДНОСТЬ

Изобретение относится к области металлургии. Для обеспечения предела прочности по меньшей мере 1200 МПа или даже 1400 МПа в сочетании с таким удлинением, что произведение Р - прочности на удлинение на разрыв имеет значение больше чем 60000 МПа % или 50000 МПа %, и однородных механических свойств горячекатаный или холоднокатаный лист выполняют из стали, химический состав которого включает (мас.%): 0.85%≤C≤1.05%; 16%≤Mn≤19%; Si≤2%; Аl≤0.050%; S≤0.030%; P≤0.050%; N≤0.1%; и при необходимости один или более элементов, выбранных из группы: Cr≤1%; Mo≤1.50%; Ni≤1%; Cu≤5%; Ti≤0.50%; Nb≤0.50%; V≤0.50%; остальное железо и неизбежные примеси, рекристаллизованная поверхность которых составляет 100%, поверхность осажденных карбидов стали составляет 0% и среднее значение размера зерна стали меньше или равно 10 микронам. Для получения горячекатаного листа полуобработанный продукт из этой стали нагревают до температуры между 1100 и 1300°С, прокатывают с температурой окончания прокатки 900°С или выше, выдерживают ...

НЕРЖАВЕЮЩАЯ СТАЛЬ ДЛЯ НЕФТЯНОЙ СКВАЖИНЫ, ТРУБА ИЗ НЕРЖАВЕЮЩЕЙ СТАЛИ ДЛЯ НЕФТЯНОЙ СКВАЖИНЫ И СПОСОБ ПОЛУЧЕНИЯ НЕРЖАВЕЮЩЕЙ СТАЛИ ДЛЯ НЕФТЯНОЙ СКВАЖИНЫ

Изобретение относится к области металлургии, в частности к нержавеющей стали для нефтяной скважины и трубе из нержавеющей стали для нефтяной скважины. Нержавеющая сталь для нефтяной скважины содержит, % по массе: С не более 0,05, Si не более 0,5, Mn от 0,01 до 0,5, Р не более 0,04, S не более 0,01, Cr свыше 16,0 и не более 18,0, Ni свыше 4,0 и не более 5,6, Мо от 1,6 до 4,0, Cu от 1,5 до 3,0, Al от 0,001 до 0,10, и N не более 0,050, причем остальное составляют Fe и примеси. Микроструктура стали содержит мартенситную фазу и ферритную фазу, имеющую объемную долю от 10 до 40%. Коэффициент распределения ферритной фазы превышает 85%. Сталь обладает высокой прочностью и коррозионной стойкостью. 3 н. и 4 з.п. ф-лы, 4 ил., 2 табл., 44 пр.

СПОСОБ ИЗГОТОВЛЕНИЯ ТОНКИХ ЛЕНТ ИЗ ФЕРРИТНОЙ НЕРЖАВЕЮЩЕЙ СТАЛИ И ЛЕНТА, ПОЛУЧЕННАЯ ЭТИМ СПОСОБОМ

Изобретение относится к области металлургии, конкретно к изготовлению тонких лент из ферритной нержавеющей стали. В процессе непрерывного литья между располагающимися рядом друг с другом двумя валками с горизонтальными осями вращения, охлаждаемыми изнутри и вращающимися в противоположных направлениях, отверждают ленту из ферритной нержавеющей стали, содержащей не более 0,012% углерода, не более 1% марганца, не более 1% кремния, не более 0,040% фосфора, не более 0,03% серы и от 16 до 18% хрома. После отливки ленту принудительно охлаждают или оставляют для естественного охлаждения, исключая тем самым ее нахождение в области превращения аустенита в феррит и карбиды, сматывают ленту в рулон при температуре в интервале от 600oС до температуры Ms мартенситного превращения, смотанную в рулон ленту оставляют для охлаждения с максимальной скоростью 300oС в час вплоть до температуры в интервале от 200oС до нормальной температуры окружающей среды, а затем ленту отжигают в замкнутом пространстве. Тонкая ...

ВЫСОКОПРОЧНАЯ МНОГОФАЗНАЯ СТАЛЬ, СПОСОБ ЕЕ ПОЛУЧЕНИЯ И ПРИМЕНЕНИЕ

Изобретение относится к области металлургии. Для обеспечения предела прочности 980 МПа, предела текучести, более или равного 500 МПа, полного удлинения, превышающего или равного 8%, холоднокатаная листовая сталь содержит в мас.% 0,05≤С≤0,15, 2≤Mn≤3%, Al≤0,1, 0,3≤Si≤1,5, Nb≤0,05, N≤0,02, 0,1≤Cr+Mo≤1, 0,0001≤В≤0,0025, 3,4×N≤Ti≤0,5, V≤0,1, S≤0,01, P≤0,05, железо и неизбежные примеси - остальное, имеет микроструктуру в поверхностной фракции между 50 и 95% мартенсита и между 5 и 50% суммы феррита и бейнита, при этом размер ферритного зерна составляет менее 10 мкм и соотношение сторон ферритного зерна находится между 1 и 3. Сталь согласно изобретению окисляется, а затем восстанавливается при отжиге в ходе этапов нагревания, выдержки и охлаждения. 3 н. и 17 з.п. ф-лы, 1 ил. ,5 табл.

СПОСОБ ПРОИЗВОДСТВА ТЕКСТУРИРОВАННОГО ЛИСТА ИЗ ЭЛЕКТРОТЕХНИЧЕСКОЙ СТАЛИ

Изобретение относится к области металлургии. Способ производства текстурированного листа из электротехнической стали включает нагревание сляба, содержащего, мас.%: C от 0,0005 до 0,005, Si от 2,0 до 4,5, Mn от 0,005 до 0,3, S и/или Se (в сумме) 0,05 или менее, растворенный Al от 0,010 до 0,04, N 0,005 или менее, остальное - Fe и неизбежные примеси, горячую прокатку сляба с получением горячекатаного листа, при необходимости, отжиг горячекатаного листа в горячей зоне, холодную прокатку горячекатаного листа в один, два или большее число проходов с промежуточным отжигом между ними и с получением холоднокатаного листа конечной толщины, отжиг холоднокатаного листа на первичную рекристаллизацию и отжиг на вторичную рекристаллизацию, при этом индекс ИС старения стального листа перед проведением конечной холодной прокатки устанавливают равным 70 МПа или менее для эффективного роста зерен с ориентацией Госса с обеспечением в результате текстурированного листа из электротехнической стали с хорошими ...

ПОДВЕРГНУТЫЙ ЧИСТОВОМУ ОТЖИГУ, ВЫСОКОПРОЧНЫЙ СТАЛЬНОЙ ЛИСТ С ПОКРЫТИЕМ, ИМЕЮЩИЙ ПОВЫШЕННЫЙ ПРЕДЕЛ ТЕКУЧЕСТИ И УЛУЧШЕННУЮ СТЕПЕНЬ РАЗДАЧИ ОТВЕРСТИЯ

Изобретение относится к области металлургии. Для повышения предела текучести и степени раздачи отверстия отожжённого холоднокатаного стального листа с покрытием способ включает получение стального листа, содержащего в мас.%: С 0,1 – 0,3, Mn 1 – 3, Si 0,5 – 3,5, Al 0,05 – 1,5, Mo + Cr в диапазоне 0,2 – 0,5, железо и неизбежные примеси - остальное, холодную прокатку листа, нанесение цинкового покрытия на холоднокатаный лист с получением холоднокатаного листа с покрытием с пределом текучести между 550 и 580 МПа и степенью раздачи отверстия ниже 10%, отжиг упомянутого стального листа после нанесения указанного цинкового покрытия, причем указанный отжиг после нанесения покрытия осуществляют при температуре 150-650°C в течение периода времени, достаточного для повышения предела текучести отожженного холоднокатаного стального листа с покрытием по меньшей мере на 40% по сравнению с холоднокатаным стальным листом непосредственно после нанесения покрытия, и увеличения степени раздачи отверстия отожженного ...

ТОЛСТОЛИСТОВАЯ СТАЛЬ ДЛЯ ВЫСОКОПРОЧНЫХ И ИМЕЮЩИХ ВЫСОКУЮ УДАРНУЮ ПРОЧНОСТЬ СТАЛЬНЫХ ТРУБ И СПОСОБ ПРОИЗВОДСТВА ТОЛСТОЛИСТОВОЙ СТАЛИ

Изобретение относится к области металлургии, а именно к толстолистовой стали для высокопрочных и имеющих высокую ударную прочность стальных труб. Сталь имеет химический состав, содержащий, мас.%: С: 0,03-0,08, Si: от более 0,05 и 0,50 или менее, Mn: 1,5-2,5, Р: 0,001-0,010, S: 0,0030 или менее, Al: 0,01-0,08, Nb: 0,010-0,080, Ti: 0,005-0,025, N: 0,001-0,006, по меньшей мере один из: Cu: 0,01-1,00, Ni: 0,01-1,00, Cr: 0,01-1,00, Мо: 0,01-1,00, V: 0,01-0,10 и В: 0,0005-0,0030, остальное - Fe и неизбежные примеси. Сталь имеет микроструктуру, в которой доля площади феррита составляет 20-80% в позиции, расположенной в 1/2 толщины толстолистовой стали, и от 50 до 100% от количества феррита представляет собой деформированный феррит. При испытании на разрыв падающим грузом при температуре -55°С на поверхности излома образца толстолистовой стали присутствуют трещины, расположенные в направлении, перпендикулярном направлению развития трещины при испытании на разрыв падающим грузом, характеризующиеся ...

ГОРЯЧЕКАТАНЫЙ СТАЛЬНОЙ ЛИСТ И СПОСОБ ЕГО ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к получению горячекатаного стального листа, используемого в качестве конструкционного материала или для изготовления промышленного оборудования. Горячекатаный стальной лист имеет состав, включающий в себя следующие элементы, мас.%: 0,18 ≤ углерод ≤ 0,3, 1,8 ≤ марганец ≤ 4,5, 0,8 ≤ кремний ≤ 2, 0,001 ≤ алюминий ≤ 0,2, 0,1 ≤ молибден ≤ 1, 0,001 ≤ титан ≤ 0,2, 0 ≤ фосфор ≤ 0,09, 0 ≤ сера ≤ 0,09, 0 ≤ азот ≤ 0,09, при необходимости по меньшей мере один из следующих элементов: 0,0001 ≤ бор ≤ 0,01, 0 ≤ хром ≤ 0,5, 0 ≤ ниобий ≤ 0,1, 0 ≤ ванадий ≤ 0,5, 0 ≤ никель ≤ 1, 0 ≤ медь ≤ 1, 0 ≤ кальций ≤ 0,005 и 0 ≤ магний ≤ 0,0010, остальное - железо и неизбежные примеси. Микроструктура стального листа содержит в долях площади по меньшей мере 75% мартенсита, состоящего из отпущенного мартенсита и свежего мартенсита, и от 8 до 25% остаточного аустенита, причем аспектное отношение остаточного аустенита составляет от 4 до 12. Лист обладает требуемым комплексом ...

Способ производства толстолистового проката для изготовления труб магистральных трубопроводов

Изобретение относится к области металлургии, а именно к производству на реверсивном стане толстолистового трубного проката для изготовления магистральных трубопроводов. Способ включает получение непрерывнолитой стальной заготовки из стали со следующим соотношением элементов, мас.%: углерод 0,03-0,07, кремний 0,10-0,35, марганец 1,00-1,60, сера не более 0,004, фосфор не более 0,015, хром не более 0,30, никель не более 0,30, медь не более 0,30, алюминий 0,02-0,05, титан 0,001-0,03, молибден не более 0,30, ванадий не более 0,10, ниобий 0,02-0,08, азот не более 0,008, бор не более 0,001, кальций 0,0005-0,006, железо и неизбежные примеси – остальное. Проводят аустенитизацию заготовки и стадии черновой и чистовой прокаток с получением готового толстолистового проката, при этом стадию черновой прокатки начинают при температуре не менее 980 °С и осуществляют ее на толщину подката, составляющую не менее 4,5 толщин готового толстолистового проката, стадию чистовой прокатки начинают при температуре ...

Способ изготовления листов из конструкционной стали

Изобретение относится к области черной металлургии, а именно к производству листового проката из конструкционных сталей, используемого для изготовления корпусов сосудов, работающих в условиях высоких температур и под давлением. Изготавливают непрерывную литую заготовку из стали, содержащей компоненты при следующем соотношении компонентов, мас.%: C 0,04–0,30, Si 0,10–0,50, Mn 0,20–0,90, Cr 1,50–3,00, Ni не более 0,40, Cu не более 0,30, Al не более 0,05, V не более 0,06, Nb не более 0,06, Mo 0,40-1,0, N не более 0,02, S не более 0,02, P не более 0,02, при необходимости B не более 0,005, остальное - железо и неизбежные примеси. Нагревают непрерывную литую заготовку до температуры аустенизации, составляющей 1150-1300°C. Проводят горячую прокатку упомянутой заготовки, при этом черновую прокатку заканчивают при температуре 900-1100°C, чистовую прокатку начинают при температуре 800-1050°C и заканчивают при температуре 730-990°C. Осуществляют охлаждение листов на воздухе до температуры не более ...

ХОЛОДНОКАТАНЫЙ И ОТОЖЖЁННЫЙ СТАЛЬНОЙ ЛИСТ И СПОСОБ ЕГО ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к высокопрочному холоднокатаному и отожженному стальному листу, используемому в качестве материала для изготовления структурных элементов и панелей кузовов транспортных средств. Лист выполнен из стали, имеющей состав, включающий в мас.%: C: 0,03-0,18, Mn: 6,0-11,0, Al: 0,2-3, Mo: 0,05-0,5, B: 0,0005-0,005, S≤0,010, P≤0,020, N≤0,008, при необходимости по меньшей мере один элемент, выбранный из: Si≤1,20, Ti≤0,050, Nb≤0,050, Cr≤0,5 и V≤0,2, остальное - железо и неизбежные примеси, образующиеся при плавке. Лист обладает микроструктурой, содержащей, в долях поверхности, от 25 до 54% остаточного аустенита, от 46 до 75% феррита и от 0 до 8% свежего мартенсита. Количества углерода [C]A и марганца [Mn]A в аустените, выраженные в массовых процентах, удовлетворяют условию [C]A*√[Mn]A, составляющему от 0,48 до 1,8. Неоднородное повторное выделение марганца с областями выше и ниже номинального значения содержания марганца в стальном листе характеризуется ...

ВЕРТИКАЛЬНАЯ ПЕЧЬ ДЛЯ НЕПРЕРЫВНОЙ ТЕРМИЧЕСКОЙ ОБРАБОТКИ МЕТАЛЛИЧЕСКОЙ ПОЛОСЫ

Изобретение относится к области термической обработки. Вертикальная печь (1) для непрерывной термической обработки металлической полосы (2), содержащая входную зону (3) для металлической полосы (2), зону (4) нагрева/выдержки с камерой отжига для нагревания и выдерживания при соответствующей температуре металлической полосы (2), первую зону (5) охлаждения для охлаждения металлической полосы (2), размещенное после первой зоны (5) охлаждения поворотное устройство (6) для поворота металлической полосы (2) по направлению к выходной зоне (8) для металлической полосы (2). Причем после поворотного устройства (6) по направлению продвижения размещена вторая зона (9) охлаждения, при этом зона (4) нагрева/выдержки и первая зона (5) охлаждения окружены восходящей ветвью (17). А восходящая ветвь (17) и включающая вторую зону (9) охлаждения нисходящая ветвь (18) соединены друг с другом поворотным устройством (6). Первая зона (5) охлаждения сформирована как зона радиационного охлаждения для металлической ...

НИЗКОПРОЧНЫЙ СТАЛЬНОЙ ЛИСТ ДЛЯ ГОРЯЧЕЙ ШТАМПОВКИ, ГОРЯЧЕШТАМПОВАННЫЙ КОМПОНЕНТ И СПОСОБ ПРОИЗВОДСТВА ГОРЯЧЕШТАМПОВАННОГО КОМПОНЕНТА

Изобретение относится к области металлургии, а именно к низкопрочному стальному листу для горячей штамповки, используемому в автомобилестроении при производстве горячештампованного элемента, имеющего предел прочности TS 500-800 МПа. Стальной лист содержит, мас.%: C: от 0,005% до 0,12%, Si: от 0,50% до 2,0%, Mn: 0,50% или меньше (не включая 0%), Al: от 0,010% до 1,0%, P: 0,1000% или меньше (не включая 0%), S: 0,0100% или меньше (не включая 0%), N: 0,0100% или меньше (не включая 0%), O: 0,0100% или меньше (не включая 0%), необязательно, по меньшей мере один из Ti: 0,10% или меньше, не включая 0%, и Nb: 0,10% или меньше, не включая 0%, остальное - железо и неизбежные примеси. Доля площади феррита на глубине 1/4 толщины стального листа составляет 80% или больше, а точка Ac3 (°C), определяемая по уравнению: Точка Ac3 (°C) = 910 - 203 × [C]1/2 + 44,7 × [Si] - 30 × [Mn] + 700 × [P] + 400 × [Al] + 400 × [Ti], где [C], [Si], [Mn], [P], [Al] и [Ti] представляют собой содержание в стали соответствующих ...

ХОЛОДНОКАТАНЫЙ ОТОЖЖЁННЫЙ СТАЛЬНОЙ ЛИСТ И СПОСОБ ЕГО ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к холоднокатаному и отожженному высокопрочному стальному листу, используемому в автомобильной промышленности. Лист выполнен из стали, имеющей состав, включающий в мас.%: C 0,03-0,18, Mn 6,0–11,0, Al 0,2–3, Mo 0,05–0,5, B 0,0005–0,005, S≤0,010, P≤0,020, N≤0,008, при необходимости по меньшей мере один элемент, выбранный из: Si≤1,20, Ti≤0,050, Nb≤0,050, Cr≤0,5 и V≤0,2, остальное - железо и неизбежные примеси, образующиеся при плавке. Стальной лист обладает микроструктурой, заключающей в себе, в долях поверхности, от 25 до 55% остаточного аустенита, от 45 до 75% феррита, от 0 до 5% свежего мартенсита. Содержание углерода [C]A и марганца [Mn]A в аустените, выраженное в мас.%, такое, что отношение ([C]A×[Mn]2A)/(C%×Mn%) составляет от 19,0 до 41,0 мас.%, при этом C% и Mn% представляют собой номинальные значения содержания углерода и марганца в стальном листе в мас.%. Плотность карбидов в микроструктуре составляет менее 3×106/мм2 и неоднородное ...

ТОНКАЯ СТАЛЬНАЯ ПЛАСТИНА СПЕЦИФИКАЦИИ NM450 И СПОСОБ ЕЕ ПОЛУЧЕНИЯ

Изобретение относится к области металлургии, а именно к стальной пластине толщиной 4-8 мм спецификации NM450, используемой в качестве материала, применяемого в рудниках, на железной дороге и в металлургии. Стальная пластина имеет следующий химический состав, в мас.%: C: 0,15-0,30, Si: 0,25-0,45, Mn: 0,80-1,20, Cr: 0,20-0,60, Mo: 0,10-0,50, Ni: 0,10-0,50, Al: 0,02-0,08, B: 0,0010-0,0030, P меньше или равняется 0,020, S меньше или равняется 0,010; остальное представляет собой Fe и неизбежные примеси. Обеспечивается получение тонких пластин, обладающих высоким уровнем механических свойств. 2 н. и 5 з.п. ф-лы, 1 табл., 3 пр.

СТАЛЬНОЙ ЛИСТ С ПОКРЫТИЕМ И ДЕТАЛЬ ИЗ ВЫСОКОПРОЧНОЙ УПРОЧНЁННОЙ ПРЕССОВАНИЕМ СТАЛИ И СПОСОБ ИХ ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к получению стальных листов с покрытием, используемых в качестве материала для изготовления на формовочном прессе конструкционных деталей или деталей безопасности транспортных средств. Стальной лист выполнен из стали, имеющей состав, содержащий в мас.%: С 0,15-0,25, Мn 0,5-1,8, Si 0,1-1,25, Al 0,01-0,1, Cr 0,1-1,0, Ti 0,01-0,1, В 0,001-0,004, Р ≤ 0,020, S ≤ 0,010, N ≤ 0,010, при необходимости по меньшей мере один из: Mo ≤ 0,40, Nb ≤ 0,08 и Са ≤ 0,1, остальное - железо и неизбежные примеси. Стальной лист с покрытием содержит основную часть, обезуглероженный слой, покрывающий основную часть, и слой покрытия из алюминиевого сплава. Основная часть листа имеет микроструктуру, содержащую в долях поверхности 60-90% феррита, при этом остальная часть представляет собой мартенситно-аустенитные островки, перлит или бейнит. Обезуглероженный слой состоит в верхней части из слоя феррита толщиной 1-100 мкм. Изготавливаемые из таких листов детали обладают ...

ВЫСОКОПРОЧНАЯ И ВЫСОКОДЕФОРМИРУЕМАЯ ЛИСТОВАЯ СТАЛЬ И СПОСОБ ЕЕ ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к холоднокатаной и термообработанной листовой стали, используемой в автомобилестроении. Сталь имеет следующий химический состав, мас.%: 0,10≤С≤0,25, 3,5≤Mn≤6,0, 0,5≤Si≤2,0, 0,3≤Al≤1,2, 0,10≤Mo≤0,50, S≤0,010, P≤0,020, N≤0,008, при необходимости один или несколько элементов, выбранных из: 0,01≤Cr≤1,0, 0,010≤Ti≤0,080, 0,010≤Nb≤0,080, 0,010≤V≤0,30 и 0,0005≤B≤0,004, остальное - железо и неизбежные примеси. Сталь обладает микроструктурой, состоящей, при выражении в поверхностных долевых концентрациях, из: от 10% до 45% феррита, характеризующегося средним размером зерен, составляющим, самое большее, 1,3 мкм, от 8% до 30% остаточного аустенита, самое большее, 8% свежего мартенсита и самое большее, 2,5% цементита и подвергшегося перераспределению мартенсита. Произведение поверхностной долевой концентрацией феррита на средний размер зерен феррита составляет, самое большее, 35 мкм%, а остаточный аустенит характеризуется уровнем содержания Mn, составляющим ...

ГОРЯЧЕКАТАНАЯ ЛИСТОВАЯ СТАЛЬ ДЛЯ ГИБКОЙ НАСОСНО-КОМПРЕССОРНОЙ ТРУБЫ МАЛОГО ДИАМЕТРА И СПОСОБ ЕЕ ИЗГОТОВЛЕНИЯ

Изобретение относится к металлургии, а именно к горячекатаной листовой стали для гибкой насосно-компрессорной трубы. Горячекатаная листовая сталь для гибкой насосно-компрессорной трубы характеризуется химическим составом, содержащим, в мас.%: С 0,10-0,16, Si 0,1-0,5, Mn 0,8-1,8, P 0,001-0,020, S 0,0050 или менее, Al 0,01-0,08, Сu 0,1-0,5, Ni 0,1-0,5, Сr 0,5-0,8, Mo 0,10-0,5, Nb 0,01-0,05, Ti 0,01-0,03, N 0,001-0,006, необязательно один или более компонентов, выбранных из В 0,0005-0,0050, V 0,01-0,10, Ca 0,0005-0,0100, редкоземельный металл 0,0005-0,0200, Zr 0,0005-0,0300 и Mg 0,0005-0,0100, Fe и неизбежные примеси - остальное, микроструктурой в позиции, расположенной на 1/2 толщины листовой стали, включающей бейнит и бейнитный феррит при совокупном количестве, составляющем 80% или более, применительно к поверхностной долевой концентрации, в которой количество Nb в состоянии твердого раствора Nb составляет 20% или более от совокупного уровня массового содержания Nb. Способ изготовления горячекатаной ...

СПОСОБ ИЗГОТОВЛЕНИЯ ЛИСТОВОЙ ТВИП-СТАЛИ, ВКЛЮЧАЮЩЕЙ АУСТЕНИТНУЮ МАТРИЦУ

Настоящее изобретение относится к способу производства листовой стали с пластичностью, наведенной двойникованием, имеющей аустенитную матрицу и используемой при изготовлении автомобильных транспортных средств. Сляб, содержащий при расчете на массу: 0,5 < C < 1,2%, 13,0 ≤ Mn < 25,0%, S ≤ 0,030%, P ≤ 0,080%, N ≤ 0,1%, Si ≤ 3,0%, 0,051% ≤ Al ≤ 4,0%, 0,1 ≤ V ≤ 2,5%, при необходимости один или несколько элементов из Nb ≤ 0,5%, B ≤ 0,005%, Cr ≤ 1,0%, Mo ≤ 0,40%, Ni ≤ 1,0%, Cu ≤ 5,0%, Ti ≤ 0,5% и 0,06 ≤ Sn ≤ 0,2%, остальное - железо и неизбежные примеси, повторно нагревают, осуществляют его горячую прокатку, скатывают в рулон, выполняют первую холодную прокатку, рекристаллизационный отжиг и вторую холодную прокатку. Обеспечивается получение листовой стали с высокими механическими свойствами. 2 н. и 21 з.п. ф-лы, 2 ил., 1 пр.

СПОСОБ ЧАСТИЧНОГО РАДИАЦИОННОГО НАГРЕВА ДЛЯ ИЗГОТОВЛЕНИЯ ДЕТАЛЕЙ ПОСРЕДСТВОМ ГОРЯЧЕЙ ШТАМПОВКИ И УСТРОЙСТВО ДЛЯ ТАКОГО ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии. Для обеспечения заданных структурных свойств малых по размеру локальных областей детали и управления ими способ (100) содержит шаги, на которых помещают (102) заготовку в печь (10) для нагревания (104) заготовки до температуры, равной или превышающей температуру аустенизации материала заготовки для перевода материала заготовки в аустенитную фазу, в установке инфракрасного (ИК) нагрева частично нагревают (106) посредством ИК излучения (24) по меньшей мере одну первую область (2а) заготовки, тем самым поддерживая материал указанной по меньшей мере одной первой области заготовки в аустенитной фазе, и помещают (108) заготовку в обрабатывающий блок (30) для формовки и закалки заготовки с целью получения горячештампованной детали. 2 н. и 15 з.п. ф-лы, 9 ил.

ТЕКСТУРИРОВАННАЯ ЭЛЕКТРОМАГНИТНАЯ ЛИСТОВАЯ СТАЛЬ И СПОСОБ ПРОИЗВОДСТВА ТЕКСТУРИРОВАННОЙ ЭЛЕКТРОМАГНИТНОЙ ЛИСТОВОЙ СТАЛИ

Изобретение относится к текстурированной электротехнической листовой стали и способу ее производства. Указанная сталь содержит листовую сталь, керамическое покрытие, расположенное на листовой стали, и изоляционное придающее натяжение оксидное покрытие, расположенное на керамическом покрытии. Керамическое покрытие содержит нитрид и оксид. Нитрид содержит по меньшей мере один элемент, выбранный из группы, состоящей из Cr, Ti, Zr, Mo, Nb, Si, Al, Ta, Hf, W и Y. Оксид обладает структурой кристалла, относящейся к корундовому типу. Модуль Юнга для керамического покрытия согласно измерению при использовании метода наноиндентирования составляет не менее чем 230 ГПа. Керамическое покрытие характеризуется средней толщиной покрытия, составляющей не менее чем 0,01 мкм и не более чем 0,30 мкм. Изоляционное придающее натяжение оксидное покрытие характеризуется натяжением, составляющим не менее чем 10 МПа. При осуществлении способа керамическое покрытие формируют посредством ионно-дугового осаждения.

ХОЛОДНОКАТАНАЯ И ОТОЖЖЕННАЯ ЛИСТОВАЯ СТАЛЬ, СПОСОБ ЕЕ ПРОИЗВОДСТВА И ИСПОЛЬЗОВАНИЕ ТАКОЙ СТАЛИ ДЛЯ ПРОИЗВОДСТВА ДЕТАЛЕЙ ТРАНСПОРТНЫХ СРЕДСТВ

Изобретение относится к области металлургии, а именно к холоднокатаной и отожженной листовой стали, используемой для изготовления деталей обеспечения безопасности или конструкционных деталей транспортных средств. Сталь содержит, мас.%: 0,6 < C < 1,3%, 15,0 ≤ Mn < 35%, 6,0 ≤ Al < 15%, Si ≤ 2,40%, S ≤ 0,015%, P ≤ 0,1%, N ≤ 0,1%, при необходимости, по меньшей мере один из Ni, Cr и Cu до 3% каждого и, при необходимости, по меньшей мере один из B, Ta, Zr, Nb, V, Ti, Mo и W в сумме до 2,0%, остальное - железо и неизбежные примеси. Микроструктура стали содержит, по меньшей мере, 0,1% внутризеренных каппа-карбидов, необязательно вплоть до 10% зернистого феррита, при этом остаток образован из аустенита. По меньшей мере 80% каппа-карбидов характеризуются средним размером, составляющим менее чем 30 нм. Средний размер зерен и среднее соотношение сторон зерен аустенита, соответственно, составляют менее, чем 6 мкм, и от 1,5 до 6, а средний размер зерен и среднее соотношение сторон зерен феррита в случае ...

СТАЛЬНАЯ ПОДЛОЖКА С ПОКРЫТИЕМ

Изобретение относится к стальной подложке с нанесенным покрытием, используемой в сталелитейной промышленности. Подложка (5) имеет следующую композицию, мас.%: 0,31 ≤ C ≤ 1,2, 0,1 ≤ Si ≤ 1,7, 0,15 ≤ Mn ≤ 1,1, P ≤ 0,01, S ≤ 0,1, Cr ≤ 1,0, Ni ≤ 1,0, Mo ≤ 0,1, при необходимости один или несколько элементов из: Nb ≤ 0,05, B ≤ 0,003, Ti ≤ 0,06, Cu ≤ 0,1, Co ≤ 0,1, N ≤ 0,01 и V ≤ 0,05, остальное - железо и неизбежные примеси. Покрытие (1) содержит чешуйки (2) нанографита с поперечным размером в диапазоне между 1 и 60 мкм, которые хорошо диспергированы в связующем (3), формируя извилистую траекторию (4). Обеспечивается снижение потери массы вследствие окисления полуфабрикатов во время проведения стадии повторного нагревания. 3 н. и 19 з.п. ф-лы, 2 ил., 1 табл., 1 пр.

ХОЛОДНОКАТАНАЯ И ТЕРМООБРАБОТАННАЯ ЛИСТОВАЯ СТАЛЬ И СПОСОБ ЕЕ ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к термообработанному и холоднокатаному стальному листу, используемому для изготовления конструкционных деталей или деталей, отвечающих за безопасность, в транспортном средстве. Лист выполнен из стали, содержащей, в мас.%: 0,18 ≤ углерод ≤ 0,24, 1,5 ≤ марганец ≤ 2,5, 1,2 ≤ кремний ≤ 2, 0,01 ≤ алюминий ≤ 0,06, 0,2 ≤ хром ≤ 0,5, фосфор ≤ 0,02, сера ≤ 0,03, при необходимости по меньшей мере один элемент из: ниобий ≤ 0,06, титан ≤ 0,08, ванадий ≤ 0,1 и кальций ≤ 0,005, остальное - железо и неизбежные примеси. Лист имеет микроструктуру, содержащую, при выражении через поверхностные долевые концентрации, от 0 % до 15 % отпущенного мартенсита, от 10 % до 15 % остаточного аустенита и необязательно вплоть до 30 % феррита, остальное образовано из бейнита. Содержание бейнита составляет не менее 55 %. На обеих поверхностях стального листа образован слой внутреннего оксида, имеющий толщину, составляющую 3 мкм или менее. Стальной лист обладает требуемыми ...

МЕЛКОЗЕРНИСТАЯ МАРТЕНСИТНАЯ НЕРЖАВЕЮЩАЯ СТАЛЬ И СПОСОБ ЕЕ ПРОИЗВОДСТВА

... 1. Мартенситный сплав с номером размера зерна по ASTM, по меньшей мере, 5, содержащий, мас.%: от примерно 0,05 до примерно 0,5 углерода; по меньшей мере, примерно 5 хрома; по меньшей мере, примерно 0,5 никеля; до примерно 15 кобальта; до примерно 8 меди; до примерно 8 марганца; до примерно 4 кремния; до примерно 6 молибдена и вольфрама; до примерно 1,5 титана; до примерно 3 ванадия; до примерно 1,7 ниобия; до примерно 0,2 алюминия и по меньшей мере, примерно 40 железа. 2. Сплав по п.1, содержащий, по меньшей мере, примерно 0,005 мас.% в сумме алюминия, кремния и титана. 3. Сплав по любому из пп.1 и 2, содержащий, по меньшей мере, примерно 2 мас.% никеля. 4. Сплав по любому из пп.1 и 2, содержащий от примерно 1 до примерно 7 мас.% никеля. 5. Сплав по любому из пп.1 и 2, содержащий до примерно 7,5 мас.% кобальта. 6. Сплав по любому из пп.1 и 2, содержащий до примерно 5 мас.% кобальта. 7. Сплав по любому из пп.1 и 2, содержащий до примерно 3 мас.% меди. 8. Сплав по любому из пп.1 и 2, содержащий ...

МАРТЕНСИТНАЯ НЕРЖАВЕЮЩАЯ СТАЛЬ И СПОСОБ ПРОИЗВОДСТВА СТАЛИ

... 1. Мартенситная нержавеющая сталь, содержащая 0,65-0,70% углерода, 0-0,025% фосфора, 0-0,020% серы, 0,20-0,50% кремния, по меньшей мере, один из следующих компонентов: более 0,0004% бора и более 0,03% азота, 0,45-0,75% марганца, 12,7-13,7% хрома, и 0-0,50% никеля, при этом все значения приведены в процентах по массе (мас.%) от общей массы стали. 2. Мартенситная нержавеющая сталь по п.1, отличающаяся тем, что содержит бор в количестве более 0,0004 до 0,006 мас.%. 3. Мартенситная нержавеющая сталь по п.1, отличающаяся тем, что содержит азот в количестве более 0,03 до 0,20 мас.%. 4. Мартенситная нержавеющая сталь по п.1, отличающаяся тем, что состоит по существу из 0,65-0,70% углерода, 0-0, 025% фосфора, 0-0,020% серы, 0,20-0,50% кремния, по меньшей мере, одного из следующих компонентов: более 0,0004% бора и более 0,03% азота, 0,45-0,75% марганца, 12,7-13,7% хрома, и 0-0,50% никеля, при этом все значения приведены в мас.% от общей массы стали, и случайных примесей. 5. Мартенситная нержавеющая ...

УДАРОПРОЧНАЯ И СТОЙКАЯ К РАЗРЫВУ СТАЛЬ ДЛЯ КОНСТРУКЦИИ КОРПУСА СУДНА И СПОСОБ ЕЁ ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к ударопрочной и стойкой к разрыву листовой стали для конструкции корпуса судна. Сталь содержит, мас.%: C: 0,06-0,12, Si: 0,05-0,60, Mn: 1,50-1,70, Al: 0,01-0,06, Ti: 0,005-0,012, Mg: 0,0005-0,003, 0 Подробнее

СПОСОБ ПРОИЗВОДСТВА ВЫСОКОПРОЧНОЙ ЛИСТОВОЙ СТАЛИ, ХАРАКТЕРИЗУЮЩЕЙСЯ ВЫСОКИМИ ПЛАСТИЧНОСТЬЮ, ДЕФОРМИРУЕМОСТЬЮ И СВАРИВАЕМОСТЬЮ, И ПОЛУЧЕННАЯ ЛИСТОВАЯ СТАЛЬ

Изобретение относится к области металлургии. Для получения листовой стали с нанесенным покрытием, обладающей заданными механическими свойствами совместно с высокой свариваемостью, в особенности высокой свариваемостью при использовании контактной точечной сварки, способ включает получение холоднокатаной листовой стали, содержащей, мас.%: 0,15 ≤ С ≤ 0,23, 1,4 ≤ Mn ≤ 2,6, 0,6 ≤ Si ≤ 1,3, при этом С + Si/10 ≤ 0,30, 0,4 ≤ Al ≤ 1,0, причем Al ≥ 6(C + Mn/10) - 2,5, 0,010 ≤ Nb ≤ 0,035, 0,1 ≤ Мо ≤ 0,5, отжиг листа при температуре в диапазоне 860-900°С для получения структуры, состоящей из по меньшей мере 90% аустенита и по меньшей мере 2% межкритического феррита, закалку до температуры в диапазоне от Ms - 10°С до Ms - 60°С при скорости Vc, составляющей более чем 30°С/с, нагрев до температуры РТ в диапазоне от 410°С до 470°С на протяжении от 60 до 130 с, нанесение на лист покрытия в результате погружения в расплав и охлаждение до комнатной температуры. Микроструктура содержит от 45 до 68% мартенсита ...

ХОЛОДНОКАТАНЫЙ СТАЛЬНОЙ ЛИСТ И СПОСОБ ЕГО ПОЛУЧЕНИЯ

Изобретение относится к области металлургии, а именно к холоднокатаному стальному листу, используемому в автомобилестроении. Лист изготовлен из стали, содержащей в мас.%: С от 0,01 до 0,4, Si от 0,001 до 2,5, Mn от 0,001 до 4,0, Al от 0,001 до 2,0, P 0,15 или менее, S 0,03 или менее, N 0,01 или менее, O 0,01 или менее, Fe и неизбежные примеси остальное. Средняя полюсная плотность ориентационной группы от {100}<011> до {223}<110> составляет от 1,0 до 5,0, а полюсная плотность ориентации кристалла {332}<113> составляет от 1,0 до 4,0 на центральном участке толщины, в диапазоне толщины от 5/8 до 3/8 от основания поверхности стального листа. Величина rC Лэнкфорда в направлении, перпендикулярном направлению прокатки, составляет от 0,70 до 1,50, а величина r30 Лэнкфорда в направлении под углом 30° к направлению прокатки составляет от 0,70 до 1,50. Структура листа состоит из: от 30% до 99% феррит и бейнит, от 1% до 70% мартенсит. Обеспечиваются повышенные равномерная и локальная деформируемости ...

СТАЛЬНОЙ ПРОДУКТ СО СРЕДНИМ СОДЕРЖАНИЕМ МАРГАНЦА ДЛЯ ИСПОЛЬЗОВАНИЯ ПРИ НИЗКИХ ТЕМПЕРАТУРАХ И СПОСОБ ЕГО ПРОИЗВОДСТВА

Изобретение относится к области металлургии, а именно к стальному продукту, предназначенному для использования при низких температурах. Сталь продукта имеет следующий химический состав, вес.%: С от 0,01 до <0,3, Мn от 4 до <10, Аl от 0,003 до 2,9, Мо от 0,01 до 0,8, Si от 0,02 до 0,8, Ni от 0,005 до 3, Р<0,04, S<0,02, N<0,02, остальное железо и неизбежные примеси. Стальной продукт удовлетворяет одному из трех вариантов. В первом варианте сталь может содержать по меньшей мере один из следующих элементов, вес.%: Ti от 0,002 до 0,5; V от 0,006 до 0,1; Сr от 0,05 до 4; Сu от 0,05 до 2; Nb от 0,003 до 0,1; В от 0,0005 до 0,014; Со от 0,003 до 3; W от 0,03 до 2; Zr от 0,03 до 1; Са<0,004 и Sn<0,5, при этом выполняется условие 6<1,5Мn+Ni<8. Во втором варианте сталь может содержать по меньшей мере один из следующих элементов, вес.%: Ti от 0,002 до 0,5; V от 0,006 до 0,1; Сr от 0,05 до 4; Сu от 0,05 до 2; Nb от 0,003 до 0,1; В от 0,0005 до 0,014; Со от 0,003 до 3; W от 0,03 до 2; Zr от 0,03 до 1 ...

СПОСОБ ИЗГОТОВЛЕНИЯ ХОЛОДНОКАТАНОЙ СТАЛЬНОЙ ПОЛОСЫ ИЗ ВЫСОКОПРОЧНОЙ, СОДЕРЖАЩЕЙ МАРГАНЕЦ СТАЛИ С TRIP-СВОЙСТВАМИ

Изобретение относится к холоднокатаной стальной полосе, изготовленной из высокопрочной, содержащей марганец стали с TRIP-свойствами. Сталь содержит, вес.%: С: от 0,0005 до 0,9, Mn: от 3,0 до 12, при необходимости один или несколько из: Al: до 10, Si: до 6, Cr: до 6, Nb: до 1,5, V : до 1,5, Ti до 1,5, Мо: до 3, Cu: до 3, Sn: до 0,5, W: до 5, Co: до 8, Zr до 0,5, Та : до 0,5, Те до 0,5, B: до 0,15, Р: макс. 0,1, в частности < 0,04, S: макс. 0,1, в частности < 0,02, N: макс. 0,1, в частности < 0,05, и Са: до 0,1, железо и неизбежные примеси – остальное. Достигается повышение технологичности изготовления стальной полосы за счет обеспечения повышения степени деформации при прокатке. 4 н. и 22 з.п. ф-лы, 1 ил., 3 табл.

ГОРЯЧЕКАТАНАЯ ТОЛСТОЛИСТОВАЯ СТАЛЬ И СПОСОБ ЕЕ ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к горячекатаной толстолистовой стали, используемой для изготовления высокопрочных сварных труб для магистральных трубопроводов. Сталь имеет химический состав, содержащий, в мас.%: С: от 0,04 до 0,08, Si: от 0,01 до 0,50, Mn: от 1,2 до 2,0, Р: от 0,001 до 0,010, S: 0,0030 или менее, Al: от 0,01 до 0,08, Nb: от 0,050 до 0,100, Ti: от 0,005 до 0,025, N: от 0,001 до 0,006, по меньшей мере один элемент, выбранный из Cu: от 0,01 до 1,00, Ni: от 0,01 до 1,00, Cr: от 0,01 до 1,00, Мо: от 0,01 до 1,00, V: от 0,01 до 0,10 и В: от 0,0005 до 0,0030, остальное - Fe и неизбежные примеси. В микроструктуре в положении на 1/2 толщины толстолистовой стали поверхностная долевая концентрация мартенсита составляет менее чем 3%, а поверхностная долевая концентрация бейнитного феррита составляет 95% или более. Бейнитный феррит имеет средний диаметр зерна, составляющий 6,0 мкм или менее. Количество выделений Nb в форме карбонитрида Nb составляет 0,025 мас.% ...

СПОСОБ ПРОИЗВОДСТВА ДЕТАЛЕЙ ШАССИ ИЗ МИКРОЛЕГИРОВАННОЙ СТАЛИ, ХАРАКТЕРИЗУЮЩЕЙСЯ УЛУЧШЕННОЙ ДЕФОРМИРУЕМОСТЬЮ В ХОЛОДНОМ СОСТОЯНИИ

Изобретение относится к способу производства детали шасси из микролегированной стали, характеризующейся улучшенной перерабатываемостью в холодном состоянии у кромок листового металла, затвердевших в холодном состоянии после механического отделения, включающему следующие далее стадии способа: получение горячекатаного штрипса или горячекатаного листового штрипса из листового металла, характеризующихся заявленной композицией сплава в массовых процентах; резка заготовки при комнатной температуре и необязательное осуществление дополнительных операций пробивки или резки; нагревание исключительно областей кромок листового металла до температуры, составляющей по меньшей мере 700°С, при времени выдержки, составляющем самое большее 10 секунд, и последующее охлаждение при использовании воздуха; холодная формовка заготовки в одну или несколько стадий для получения детали шасси при комнатной температуре. 2 н. и 13 з.п. ф-лы.

СТАЛЬНОЙ ЛИСТ С ОЧЕНЬ ВЫСОКИМИ МЕХАНИЧЕСКИМИ СВОЙСТВАМИ, ТАКИМИ, КАК МЕХАНИЧЕСКАЯ ПРОЧНОСТЬ И ПЛАСТИЧНОСТЬ, СПОСОБ ИЗГОТОВЛЕНИЯ ТАКИХ ЛИСТОВ И ИХ ПРИМЕНЕНИЕ

ГОРЯЧЕШТАМПОВАННАЯ СТАЛЬ, ХОЛОДНОКАТАНЫЙ СТАЛЬНОЙ ЛИСТ И СПОСОБ ПРОИЗВОДСТВА ГОРЯЧЕШТАМПОВАННОЙ СТАЛИ

СТАЛЬНОЙ ЛИСТ С ПОКРЫТИЕМ ИЗ СИСТЕМЫ НА ОСНОВЕ ZN-AL-MG, ПОЛУЧЕННЫМ ПОГРУЖЕНИЕМ В РАСПЛАВ, ИМЕЮЩИЙ ПРЕВОСХОДНУЮ СПОСОБНОСТЬ К ОБРАБАТЫВАЕМОСТИ, И СПОСОБ ЕГО ИЗГОТОВЛЕНИЯ

СПОСОБ ИЗГОТОВЛЕНИЯ СВЕРХПРОЧНОГО СТАЛЬНОГО ЛИСТА С ПОКРЫТИЕМ ИЛИ БЕЗ ПОКРЫТИЯ И ПОЛУЧЕННЫЙ ЛИСТ

РЕЖУЩИЕ ЭЛЕМЕНТЫ ДЛЯ БРИТВ

... 1. Бритвенное лезвие, содержащее краевой участок с режущей кромкой и дополнительный участок, причем краевой участок изогнут относительно дополнительного участка в изгибной зоне, отстоящей от режущей кромки, отличающееся тем, что по меньшей мере краевой участок имеет структуру материала, упрочненную термообработкой, при этом изгибная зона характеризуется локально повторно нагретой структурой. ! 2. Бритвенное лезвие, содержащее тело лезвия, включающее краевой участок с режущей кромкой, при этом режущая кромка характеризуется твердостью, превышающей твердость участка тела лезвия, а режущая кромка локально упрочнена селективной термообработкой. ! 3. Бритвенное лезвие по п.1, отличающееся тем, что термообработка, использованная для упрочнения краевого участка, содержит термообработку лазером. ! 4. Бритвенное лезвие по п.1 или 3, отличающееся тем, что локально повторно нагретая структура нагрета повторно с помощью энергии лазера. ! 5. Бритвенное лезвие по п.1, отличающееся тем, что локально повторно ...

СПОСОБ ПРОИЗВОДСТВА СТАЛЬНОГО ЛИСТА С ПОКРЫТИЕМ, ИМЕЮЩЕГО ПОВЫШЕННУЮ ПРОЧНОСТЬ, ПЛАСТИЧНОСТЬ И ДЕФОРМИРУЕМОСТЬ

ГОРЯЧЕКАТАНЫЙ СТАЛЬНОЙ ЛИСТ И СООТВЕТСТВУЮЩИЙ СПОСОБ ИЗГОТОВЛЕНИЯ

Способ изготовления высокопрочного стального листа и полученный лист

СПОСОБ ИЗГОТОВЛЕНИЯ ВЫСОКОПРОЧНОГО СТАЛЬНОГО ЛИСТА, ОБЛАДАЮЩЕГО УЛУЧШЕННОЙ ФОРМУЕМОСТЬЮ И ПЛАСТИЧНОСТЬЮ, И ПОЛУЧЕННЫЙ ЛИСТ

СВЕРХВЫСОКОПРОЧНАЯ ЗАКАЛИВАЮЩАЯСЯ НА ВОЗДУХЕ, МНОГОФАЗНАЯ СТАЛЬ, ОБЛАДАЮЩАЯ ОТЛИЧНЫМИ ТЕХНОЛОГИЧЕСКИМИ ХАРАКТЕРИСТИКАМИ, И СПОСОБ ПОЛУЧЕНИЯ УКАЗАННОЙ СТАЛИ

ВЫСОКОПРОЧНЫЙ СТАЛЬНОЙ ЛИСТ - СТАЛЬНОЙ ЛИСТ И ВЫСОКОПРОЧНЫЙ ГАЛЬВАНИЗИРОВАННЫЙ СТАЛЬНОЙ ЛИСТ, ОБЛАДАЮЩИЕ ПРЕВОСХОДНОЙ СТАБИЛЬНОСТЬЮ ФОРМЫ, И СПОСОБ ИХ ПРОИЗВОДСТВА

... 1. Высокопрочный стальной лист, обладающий превосходной стабильностью формы, содержащий:в % мас.,C: от 0,075% до 0,300%,Si: от 0,30% до 2,5%,Mn: от 1,3% до 3,50%,P: от 0,001% до 0,030%,S: от 0,0001% до 0,0100%,Al: от 0,080% до 1,500%,N: от 0,0001% до 0,0100,O: от 0,0001% до 0,0100; иостаток, состоящий из железа и неизбежных примесей, в котором:структура стального листа содержит от 5% до 20% в объемной доле фазы остаточного аустенита в диапазоне от 1/8 толщины до 3/8 толщины стального листа; причемколичество углерода в твердом растворе, содержащегося в фазе остаточного аустенита, составляет от 0,80% до 1,00% в % мас.;значение W, определяемое как количество кремния в твердом растворе, содержащегося в фазе остаточного аустенита, в 1,10 раза или больше превосходит значение W, определяемое как среднее количество кремния в диапазоне от 1/8 толщины до 3/8 толщины стального листа;значение W, определяемое как количество марганца в твердом растворе, содержащегося в фазе остаточного аустенита, в 1,10 ...

НЕРЖАВЕЮЩАЯ СТАЛЬ ДЛЯ НЕФТЯНОЙ СКВАЖИНЫ, ТРУБА ИЗ НЕРЖАВЕЮЩЕЙ СТАЛИ ДЛЯ НЕФТЯНОЙ СКВАЖИНЫ И СПОСОБ ПОЛУЧЕНИЯ НЕРЖАВЕЮЩЕЙ СТАЛИ ДЛЯ НЕФТЯНОЙ СКВАЖИНЫ

... 1. Нержавеющая сталь для нефтяной скважины, включающая:химический состав, включающий: С - не более 0,05%, Si - не более 0,5%, Mn - от 0,01 до 0,5%, Р - не более 0,04%, S - не более 0,01%, Cr - свыше 16,0 и не более 18,0%, Ni - свыше 4,0 и не более 5,6%, Mo - от 1,6 до 4,0%, Cu - от 1,5 до 3,0%, Al - от 0,001 до 0,10% и N - не более 0,050%, причем остальное составляют Fe и примеси, и удовлетворяющий соотношениям (1) и (2)Cr+Cu+Ni+Mo≥25,5; (1)-8≤30(C+N)+0,5Mn+Ni+Cu/2+8,2-1,1(Cr+Mo)≤-4, (2)где содержание (мас.%) элемента показано символом элемента в соотношениях (1) и (2);микроструктуру, содержащую мартенситную фазу и ферритную фазу, имеющую объемную долю от 10 до 40%, и причем таким образом, что, когда многочисленные воображаемые линейные сегменты, каждый из которых имеет длину 50 мкм по направлению толщины от поверхности нержавеющей стали, размещенные в ряд с интервалами 10 мкм в пределах диапазона 200 мкм, помещают на поперечное сечение нержавеющей стали, отношение числа воображаемых линейных ...

ВЫСОКОТВЕРДАЯ ГОРЯЧЕКАТАНАЯ СТАЛЬНАЯ ПРОДУКЦИЯ И СПОСОБ ЕЕ ПРОИЗВОДСТВА

АУСТЕНИТНАЯ СТАЛЬ, ИМЕЮЩАЯ ВЫСОКУЮ ПРОЧНОСТЬ И ФОРМУЕМОСТЬ, СПОСОБ ПОЛУЧЕНИЯ УПОМЯНУТОЙ СТАЛИ И ЕЕ ПРИМЕНЕНИЕ

... 1. Аустенитная сталь, имеющая высокую прочность и хорошую формуемость для холодной прокатки, содержащая, мас.%: С 0,05-0,78 Mn 11,0-14,9 Al 1,0-5,0 Ni 0-2,5, остатком является железо и неизбежные примеси, в которой микроструктура содержит, по меньшей мере, 80 об.% аустенита, и в которой (Ni+Mn) составляет от 11,0 до 15,9%. 2. Сталь по п.1, в которой микроструктура содержит, по меньшей мере, 85%, предпочтительно, по меньшей мере, 90%, более предпочтительно, по меньшей мере, 95 об.% аустенита. 3. Сталь по п.1 или 2, в которой содержание углерода составляет от 0,30 до 0,75%. 4. Сталь по п.1 или 2, в которой содержание никеля составляет не более 0,05%. 5. Сталь по п.1 или 2, в которой содержание алюминия составляет не более 4,0%. 6. Сталь по п.1 или 2, в которой содержание марганца составляет, по меньшей мере, 11,5%, предпочтительно, по меньшей мере, 12,0%. 7. Сталь по п.1 или 2, в которой содержание марганца составляет не более 14,7%. 8. Сталь по п.1 или 2, полученная в форме горячекатаной ...

ИЗНОСОСТОЙКАЯ СТАЛЬНАЯ ПОЛОСА И СПОСОБ ЕЕ ПРОИЗВОДСТВА

... 1. Износостойкая стальная полоса, имеющая следующий химический состав, вес.%: C 0,205-0,25, Si 0,20-1,00, Mn 1,0-1,5, P≤0,015, S≤0,010, Al 0,02-0,04, Ti 0,01-0,03, N≤0,006, Ca≤0,005, и более одного элемента из следующих: Cr≤0,70, Ni≤0,50, Mo≤0,30, остальное Fe и неустранимые включения.2. Стальная полоса по п. 1, отличающаяся тем, что ее углеродный эквивалент Ceq составляет 0,57-0,64.3. Стальная полоса по п. 1 или 2, отличающаяся тем, что содержание С составляет 0,205-0,245 вес.%.4. Стальная полоса по п. 1, отличающаяся тем, что содержание Si составляет 0,20-0,99 вес.%.5. Стальная полоса по п. 1, отличающаяся тем, что содержание Mn составляет 1,11-1,45 вес.%.6. Стальная полоса по п. 1, отличающаяся тем, что содержание P≤0,009 вес.%.7. Стальная полоса по п. 1, отличающаяся тем, что содержание S≤0,004 вес.%.8. Стальная полоса по п. 1, отличающаяся тем, что содержание Al составляет 0,021-0,039 вес.%.9. Стальная полоса по п. 1, отличающаяся тем, что содержание Ti составляет 0,013-0,022 вес.% ...

ВЫСОКОПРОЧНЫЙ, ГАЛЬВАНИЗИРОВАННЫЙ ГОРЯЧИМ СПОСОБОМ СТАЛЬНОЙ ЛИСТ И СПОСОБ ЕГО ПОЛУЧЕНИЯ

... 1. Гальванизированный горячим способом стальной лист, причем стальной лист содержит, мас.%:C 0,10 - 0,4Si 0,01 - 0,5Mn 1,0 - 3,00 0,006 или менееP 0,04 или менееS 0,01 или менееAl 0,1 - 3,0N 0,01 или менееSi+Al≥0,5 остальное Fe и неизбежные примеси,при этом стальной лист является высокопрочным, гальванизированным горячим способом стальным листом, содержащим в качестве основной фазы в единицах объемной доли 40% или более феррита и от 8 до 60% остаточного аустенит, причем балансовая структура состоит из любого одного компонента или двух или более компонентов из бейнита, мартенсита и перлита,при этом из аустенита, аустенитное зерно, имеющее среднее остаточное напряжение σR, удовлетворяющее формуле (1), составляет 50% или более:-400 МПа ≤ σR ≤ 200 МПа (1)и при этом стальной лист имеет на поверхности полученный способом горячей гальванизации слой, содержащий Fe в количестве менее чем 7 мас.%, остальное Zn, Al и неизбежные примеси.2. Гальванизированный горячим способом стальной лист по п. 1, ...

СПОСОБ ИЗГОТОВЛЕНИЯ ДЕТАЛИ ПУТЕМ ГОРЯЧЕЙ ДЕФОРМАЦИИ СТАЛЬНОЙ ЗАГОТОВКИ

ЧАШИ ИЗ ТУГОПЛАВКИХ МЕТАЛЛОВ

... 1. Способ изготовления чаши, предусматривающий (a) разрезание болванки, содержащей компонент из тугоплавкого металла, в первую заготовку; (b) подвергание штамповке-высадке первой заготовки и таким образом формование второй заготовки; (c) подвергание второй заготовки первой стадии отжига в вакууме или инертном газе до первой температуры, которая является достаточно высокой, чтобы вызвать, по меньшей мере, частичную рекристаллизацию второй заготовки, и таким образом формование отожженной второй заготовки; (d) повторную штамповку отожженной второй заготовки путем уменьшения диаметра второй заготовки и таким образом формование третьей заготовки; (e) подвергание третьей заготовки штамповке-высадке и таким образом формование четвертой заготовки; (f) повторную штамповку четвертой заготовки путем уменьшения диаметра четвертой заготовки и таким образом, формование пятой заготовки; (g) подвергание пятой заготовки второй стадии отжига пятой заготовки до температуры, которая является достаточно высокой ...

СТАЛЬ ДЛЯ ГОРЯЧЕЙ ШТАМПОВКИ ИЛИ ЗАКАЛКИ В ИНСТРУМЕНТЕ, ОБЛАДАЮЩАЯ УЛУЧШЕННОЙ ПЛАСТИЧНОСТЬЮ

... 1. Стальная деталь из стали с содержанием, мас.%: ! 0,040≤С≤0,100; ! 0,80≤Mn≤2,00; ! Si≤0,30; ! S≤0,005; ! P≤0,030; ! 0,010≤Al≤0,070; ! 0,015≤Nb≤0,100; ! 0,030≤Ti≤0,080; ! N≤0,09; ! Cu≤0,100; ! Ni≤0,100; ! Cr≤0,100; ! Mo≤0,100; ! Са≤0,006, ! остальное: железо и неизбежные примеси, образующиеся в результате плавки, и микроструктура указанной стали состоит, по меньшей мере, из 75% равноосного феррита, мартенсита в количестве не менее 5%, но не более 20%, и бейнита в количестве не превышающем 10%. ! 2. Стальная деталь по п.1, отличающаяся содержанием в указанной стали, мас.%: ! 0,050≤С≤0,080; ! 1,20≤Mn≤1,70; ! Si≤0,070; ! S≤0,004; ! P≤0,020; ! 0,020≤Al≤0,040; ! 0,030≤Nb≤0,070; ! 0,060≤Ti≤0,080; ! N≤0,009; ! Cu≤0,100; ! Ni≤0,100; ! Cr≤0,100; !Mo≤0,100; ! Са≤0,005, ! остальное: железо и неизбежные примеси, образующиеся в результате плавки. ! 3. Стальная деталь по п.1 или 2, отличающаяся тем, что средний размер зерна феррита в структуре указанной стали составляет менее 6 мкм. ! 4. Стальная деталь ...

VERFAHREN ZUR HERSTELLUNG EINES STAHLBLECHES MIT HOHER KORROSIONSBESTÄNDIGKEIT

METALLURGISCHES GEFÄSS

ROSTFREIER MARTENSIT-STAHL MIT AUSGEZEICHNETER OXYDATIONSBESTAENDIGKEIT, VERARBEITBARKEIT UND KORROSIONSBESTAENDIGKEIT SOWIE HERSTELLUNGSVERFAHREN.

This improved martensitic stainless steel plate contains C (0.40 wt.% or less), Mn (1.0 wt.% or less), Ni (0.6 wt.% or less), Cr (10-14 wt.%), Al (0.025-0.30 wt.%), N (0.025-0.060 wt.%) with Fe and inevitable impurities the remaining wt.%. The content of Al is pref. maintained within 0.05-0.20 wt.% and/or the content of N within 0.03-0.05 wt.%. The plate can be produced as follows, (1) hot-rolling the steel material having the above mentioned composition, (2) softening it at 650-900 deg.C for a time shorter than 300 seconds, (3) pickling and washing with an acid soln., (4) cold-rolling, (5) finish-annealing.

Verfahren zum Erzeugen von Warmbändern aus Leichtbaustahl

Die vorliegende Erfindung betrifft ein Verfahren zum Erzeugen von Warmbändern aus einem umformbaren, insbesondere gut kalt tiefziehfähigen, Leichtbaustahl, bestehend aus den Hauptelementen Fe, Mn, Si und Al, der eine hohe Zugfestigkeit und TRIP- und/oder TWIP-Eigenschaften aufweist, wobei eine Schmelze in einer horizontalen Bandgießanlage endabmessungsnah zu einem Vorband im Bereich zwischen 6 und 20 mm unter Schutzgas vergossen und nach der Durcherstarrung und vor Beginn eines Warmwalzprozesses das Vorband temperaturmäßig eingestellt wird, das dadurch gekennzeichnet ist, dass das Vorband eine unter Schutzgas stehende Einrichtung zur Homogenisierung in Verbindung mit einem wahlweisen Halten der Temperatur, Kühlen oder Heizen durchläuft und danach einem mindestens einen Stich aufweisenden Warmwalzprozess mit einem Gesamtumformgrad von mindestens 50% unterzogen und nach einem Abkühlen als Warmband gehaspelt wird, wobei in Abhängigkeit des Verhältnisses von Gießgeschwindigkeit zu Walzgeschwindigkeit ...

LEGIERUNG FUER GLAS-METALL-DICHTUNGEN

Verfahren zur Herstellung von Bändern aus Stahl, insbesondere zur Herstellung von Schneid- und Zerspanwerkzeugen mit verbesserter Standzeit

Die Erfindung betrifft ein Verfahren zur Herstellung von Bändern aus Stahl, insbesondere zur Herstellung von Schneid- oder Zerspanwerkzeugen mit verbesserter Standzeit, bei dem ein Vorband aus einer Schmelze eines härtbaren Stahls im Gießverfahren erzeugt und anschließend zu einem Warmband ausgewalzt und erforderlichenfalls anschließend geglüht und kaltgewalzt wird. Dabei wird das Vorband in einer horizontalen Bandgießanlage hergestellt wobei die Schmelze aus einem Zulaufgefäß auf ein über zwei Umlenkrollen umlaufendes gekühltes Förderband aufgegeben und strömungsberuhigt und biegefrei zu einem Vorband im Bereich zwischen 6 und 40 mm vergossen, anschließend zu Warmband mit einem Umformgrad von mindestens 50% gewalzt, wobei die Abkühlgeschwindigkeit an Ober- und Unterseite des Vorbandes im Hinblick auf eine außermittige Resterstarrung unterschiedlich eingestellt wird.

PROCESS FOR PRODUCING CORROSION-RESISTANT ALLOY STEEL

Ferritisch rostfreier Stahl mit guter Verformbarkeit bei Raumtemperatur und mit guten mechanischen Eigenschaften bei höheren Temperaturen, und Verfahren zur Herstellung derselben

Höchstfester Mehrphasenstahl und Verfahren zur Herstellung eines kaltgewalzten Stahlbandes hieraus

Die Erfindung betrifft einen höchstfesten Mehrphasenstahl mit Dualphasengefüge oder Komplexphasengefüge sowie geringen Anteilen von Restaustenit insbesondere für den Fahrzeugleichtbau, ein Verfahren zur Herstellung von kaltgewalzten Stahlbändern aus einem solchen Stahl sowie damit hergestellte Stahlbänder. In Bezug auf ein neues Legierungskonzept mit dem das Prozessfenster für die Durchlaufglühung von Kaltbändern erweitert werden kann, wird ein Mehrphasenstahl mit einer Mindestzugfestigkeit von 980 MPa enthaltend (Gehalte in Gew.-%): C ≥ 0,075 bis ≤ 0,115, Si ≥ 0,400 bis ≤ 0,500, Mn ≥ 1,900 bis ≤ 2,350, Cr ≥ 0,250 bis ≤ 0,400, Al ≥ 0,005 bis ≤ 0,060, N ≥ 0,0020 bis ≤ 0,0120, S ≤ 0,0020, Nb ≥ 0,005 bis ≤ 0,060, Ti ≥ 0,005 bis ≤ 0,060, B > 0,0005 bis ≤ 0,0010, Mo > 0,200 bis ≤ 0,300, Ca > 0,0010 bis ≤ 0,0060, Cu ≤ 0,050, Ni ≤ 0,050, Rest Eisen, einschließlich üblicher stahlbegleitender erschmelzungsbedingter Verunreinigungen, bei dem im Hinblick auf ein möglichst breites Prozessfenster bei ...

Improvements in or relating to steel strip for use in making razor blades

A method of making chrome-nickel steel strip for use in making stainless razor blades comprises successively subjecting an age hardenable austenitic stainless chrome-nickel strip to annealing at 1000 DEG C., cooling it in air or a liquid and subsequently cold reducing it by at least 50% so that the decomposition of the metastable austenite into martensite occurs and whereupon the strip is age hardened at a temperature between 400 DEG C. and 500 DEG C. In a first example, strip having a composition of C 0.1%, Si 1%, Mn 1%, Cr 17%, Ni 7%, Ti 0.7%, remainder Fe, was cold rolled, after annealing at 1000 DEG C. and air cooling, from 0.5 mm. to 0.1 mm. and tempered at 500 DEG C. for 1 hour, to obtain a hardness value of 590 V.P.N. In a second example, strip comprising C 0.08%, Si 1.20%, Mn 1.20%, Cr 17.50%, Ni 8.0%, Mo 0.8%, remainder Fe, was similarly annealed, cold rolled from 0.9 mm. to 0.1 mm. and tempered at 460 DEG C. for 1 hour to obtain a hardness of 600-680 V.P.N. In a third example, ...

A method of controlling the microstructure of a metal article

GLASS-METAL SEALING ALLOY

... 1430517 Glass-metal sealing alloy ALLEGHENY LUDLUM INDUSTRIES Inc 20 Sept 1974 [21 Sept 1973] 41059/74 Heading C7A An alloy of composition- Balance Fe and impurities which include: - The alloy may be prepared by vacuum induction melting, solidifying, hot and cold rolling to intermediate gauge, annealing for 3 minutes in hydrogen at 1925 F, cold rolling to final size and annealing for 1¢ minutes at 1925‹F. The alloy may be used for glass to metal seals e.g. anode caps in T.V. tubes.

Stainless steels for gaming coins and method of producing gaming coins of stainless steel.

Shadow mask for colour crt and method of fabricating the same

A shadow mask for a color CRT is made of an Re-Ni series alloy, preferably consisting of 35 # 38% Ni, 0.1 # 1.0% Mn. 0.05 # 0.5% Cr, 0.05 # 0.01% B, below 0.02% C, 0.001 # 8.0% Co, 0.001 # 0.01% N, below 0.008% O, below 0.1% of at least one of Ti, Er, Mo, V, Nb, Be, P, and the balance of Fe by weight, and has a {100} cube orientation crystal plane concentration of 15 # 35% and an average grain size of 3 # 15Ám. The method of making the shadow mask includes the steps of hot rolling and annealing a slab of Fe-Ni alloy, obtained either by melting in a converter or an electric furnace and casting into an ingot and rolling, or by continuous casting, cold rolling the plate so formed for a first time and annealing for a first time, cold rolling for a second time and annealing for a second time, temper rolling and annealing to obtain a thin plate having a 15 # 35% concentration of a {100} crystal planes, with a 3 # 15Ám average grain size, applying a coat of photoresist, exposing and developing ...

Manufacture of austenitic stainless steel plates

An austenitic stainless steel plate containing up to 0.08 wt. % of carbon, up to 1.0 wt. % of silicon, up to 2.0 wt. % of manganese, 8.0-16.0 wt. % of nickel, 16.0-20.0 wt. % of chromium, 0-30 wt. % of molybdenum, up to 0.25 wt. % of nitrogen and the balance of iron and inherent impurities, is manufactured by rolling a stainless steel blank at a temperature higher than TR( DEG C.)=940+30(%Mo), and then cooling the rolled blank from a temperature above 800 DEG C. to a temperature below 500 DEG C. at a cooling speed higher than Rc ( DEG C./sec.) shown by the following equations: log (Rc)=-0.32+14(%C+%N)-0.067(%Mo) when (%C+%N)1.0 wt. %.

Method for the production of cutlery

... 846,049. Making cutlery. MALZACHER, H. April 23, 1958 [April 27, 1957], No. 12950/58. Classes 83 (2) and 83 (4). In a method of making cutlery, including hot forming and subsequently quench hardening, the cutting edge is cold-formed between said hot-forming and quenching operations, the articles being heated for a time of the usual length for quench-heating to a temperature within the range 50‹ to 100‹ C. above the transformation temperature prior to quenching. An ingot of chromium steel, preferably with a hypereutectoid initial structure is first hotrolled or hot-forged to form a knife blade and then reduced at the cutting edge by cold-forging cold-pressing or cold-rolling so that on subsequent quenching the amount of carbides in solution is increased. The cold reduction must be at least 5% and is preferably 10-20%. Annealing may also be carried out between the hot and cold-forming steps. In relating prior art the Specification also refers to carbideforming alloying constituents such as ...

PROCEDURE FOR MAKING SHEET METALS OF OUT TENITI STEEL WITH FINE GRAIN

PROCEDE DE FABRICATION D'ACIER

HIGH-FIRM, COLD-TRANSFORM-CASH STEEL AND STEEL STRIP OR - SHEET METAL, PROCEDURE FOR THE PRODUCTION OF STEEL STRIP AND USES OF SUCH A STEEL

PROCEDURE FOR THE PRODUCTION OF A VOLUME OR A FROM A VOLUME COLD-ROLLED FROM MARTENSITE-HARDENING STEEL OF LOW-CUT WORKPIECE

VERFAHREN UND ANLAGE ZUM HERSTELLEN VON EDELSTAHLBAND

PROCEDURE FOR THE CONTINUOUS PRODUCTION OF STEEL COLD-ROLLED

PROCEDURE FOR THE PRODUCTION OF A HIGH-STRENGTH PART

PROCEDURE FOR MAKING SHEET METALS AND BAENDERN OF FERRITIC ONES, STABILIZED ONES, STAINLESS ONE CHROME MOLYBDENUM NICKEL STEEL

Bestimmung des ferritischen Phasenanteils nach dem Erwärmen oder Abkühlen eines Stahlbands

The invention relates to a method for determining the ferrite phase fraction x after heating or when cooling a steel strip (2) in a metallurgic system. The invention further relates to a device for carrying out the method. The problem addressed by the invention is that of indicating a method, by means of which the ferrite phase fraction in the steel strip (2) can be determined online, quickly and with the easiest means possible. The problem is solved by a method comprising the following process steps: measuring a width w 1 and a temperature T 1 of the steel strip (2), wherein the steel strip (2) comprises a ferrite phase fraction x1 during the measurements; heating or cooling the steel strip (2), wherein in the steel strip (2) when heating a phase conversion from the ferrite state into the austenitic state at least in part and when cooling a phase conversion from the austenitic state into the ferrite state at least in part occurs; measuring of a width w and a temperature T of steel strip ...

PROCEDURE AND DEVICE FOR THE PRODUCTION OF A NICHTOXYDIERBAREN HALBFERRETI STEEL STRIP MADE OF LIQUID METAL

Method and apparatus for hot forming and hardening a blank

A blank cut from a strip of hardenable hot-formed steel is heated in a furnace to a temperature which is smaller than an Ac 3 transformation point in an iron carbon diagram. A first region of the blank is then heated in a conductive heating station to a temperature above the Ac 3 transformation point and subsequently hardened in a hot forming and hardening tool to produce a steel part with at least two microstructured regions of different ductility.

High strength steel pipe for low-temperature usage having excellent buckling resistance and toughness of welded heat affected zone and method for producing the same

An APIX100-grade high strength steel pipe includes a base material containing, in mass percentage, C: more than 0.03% and 0.08% or less, Si: 0.01% to 0.5%, Mn: 1.5% to 3.0%, P: 0.015% or less, S: 0.005% or less, Al: 0.01% to 0.08%, Nb: 0.005% to 0.025%, Ti: 0.005% to 0.025%, N: 0.001% to 0.010%, O: 0.005% or less, and B: 0.0003% to 0.0020%, further contains one or more of Cu, Ni, Cr, Mo, and V, satisfies 0.19≦P cm ≦0.25, the balance being Fe and unavoidable impurities, and has a TS of 760 to 930 MPa, a uniform elongation of 5% or more, and a YR of 85% or less; the seam weld metal has a specific composition.

High-strength steel sheet, hot-dipped steel sheet, and alloy hot-dipped steel sheet that have excellent fatigue, elongation, and collision characteristics, and manufacturing method for said steel sheets

This high-strength steel sheet includes: in terms of percent by mass, 0.03 to 0.10% of C; 0.01 to 1.5% of Si; 1.0 to 2.5% of Mn; 0.1% or less of P; 0.02% or less of S; 0.01 to 1.2% of Al; 0.06 to 0.15% of Ti; and 0.01% or less of N; and contains as the balance, iron and inevitable impurities, wherein a tensile strength is in a range of 590 MPa or more, and a ratio between the tensile strength and a yield strength is in a range of 0.80 or more, a microstructure includes bainite at an area ratio of 40% or more and the balance being either one or both of ferrite and martensite, a density of Ti(C,N) precipitates having sizes of 10 nm or smaller is in a range of 10 10 precipitates/mm 3 or more, and a ratio (Hvs/Hvc) of a hardness (Hvs) at a depth of 10 μm from a surface to a hardness (Hvc) at a center of a sheet thickness is in a range of 0.85 or more.

Thin joint member producing method and pair of thin joint members

A method is provided for producing a joint member of a metal joint, such that reduction of assembly manhours and reduction of the thickness and weight can be achieved at the same time without reducing the strength of a product or increasing the cost of production. In the case of a nut-side thin joint member, a metal plate of boron steel obtained by adding boron to low-carbon steel is burred such that the resulting cylindrical body obtains a surface that is sufficient for threading, then a threaded portion having a plurality of threads is formed on that surface, after which, quenching is carried out to increase the strength of the threads so that a nut having sufficient strength can be integrally provided even though the thickness and weight of the joint member are reduced.

METHOD FOR MANUFACTURING GRAIN ORIENTED ELECTRICAL STEEL SHEET

The present invention provides a method for manufacturing a grain oriented electrical steel sheet, including preparing as a material a steel slab having a predetermined composition and carrying out at least two cold rolling operations, characterized in that a thermal treatment is carried out, prior to any one of cold rolling operations other than final cold rolling, at temperature in the range of 500° C. to 750° C. for a period in the range of 10 minutes to 480 hours. The grain oriented electrical steel sheet of the present invention exhibits through utilization of austenite-ferrite transformation superior magnetic properties after secondary recrystallization. 1. A method for manufacturing a grain oriented electrical steel sheet , comprising the steps ofsubjecting a steel slab having a composition containing by mass %, C: 0.020% to 0.15% (inclusive of 0.020% and 0.15%), Si: 2.5% to 7.0% (inclusive of 2.5% and 7.0%), Mn: 0.005% to 0.3% (inclusive of 0.005% and 0.3%), acid-soluble aluminum: 0.01% to 0.05% (inclusive of 0.01% and 0.05%), N: 0.002% to 0.012% (inclusive of 0.002% and 0.012%), at least one of S and Se by the total content thereof being 0.05% or less, and the balance as Fe and incidental impurities to heating and subsequent hot rolling to obtain a hot rolled steel sheet;subjecting the hot rolled steel sheet optionally to hot-band annealing and essentially to at least two cold rolling operations with intermediate annealing therebetween to obtain a cold rolled steel sheet having final sheet thickness; andsubjecting the cold rolled steel sheet to primary recrystallization annealing and then secondary recrystallization annealing,wherein a thermal treatment is carried out, prior to any one of cold rolling operations other than final cold rolling, at temperature in the range of 500° C. to 750° C. (inclusive of 500° C. and 750° C.) for a period in the range of 10 minutes to 480 hours (inclusive of 10 minutes and 480 hours).2. The method for manufacturing a grain ...

HIGH-STRENGTH HOT-ROLLED STEEL SHEET HAVING EXCELLENT FORMABILITY AND METHOD FOR MANUFACTURING THE SAME

A high-strength hot-rolled steel sheet has a composition including C: 0.005% or more and 0.050% or less, Si: 0.2% or less, Mn: 0.8% or less, P: 0.025% or less, S: 0.01% or less, N: 0.01% or less, Al: 0.06% or less, and Ti: 0.05% or more and 0.10% or less, on a mass percent basis, such that S, N, and Ti satisfy Ti≧0.04+(N/14×48+S/32×48), the remainder being Fe and incidental impurities; a matrix in which a ferrite phase constitutes 95% by area or more of the entire structure; and a structure in which Ti-containing fine carbide having an average grain size of less than 10 nm is dispersedly precipitated, and the volume ratio of the fine carbide to the entire structure is 0.0007 or more. 1. A high-strength hot-rolled steel sheet having excellent formability , comprising: C: 0.005% or more and 0.050% or less, Si: 0.2% or less,', 'Mn: 0.8% or less, P: 0.025% or less,', 'S: 0.01% or less, N: 0.01% or less,', {'br': None, 'Ti≧0.04+(N/14×48+S/32×48)\u2003\u2003(1)'}, 'Al: 0.06% or less, and Ti: 0.05% or more and 0.10% or less, on a mass percent basis, such that S, N, and Ti satisfy Formula (1), the remainder being Fe and incidental impurities; a matrix in which a ferrite phase constitutes 95% by area or more of the entire structure; and a structure in which Ti-containing fine carbide having an average grain size of less than 10 nm is dispersedly precipitated, and volume ratio of the fine carbide to the entire structure is 0.0007 or more, wherein the high-strength hot-rolled steel sheet has a tensile strength of 590 MPa or more], 'a composition comprising'}wherein S, N, and Ti denote their respective contents (% by mass).5. The steel sheet according to claim 1 , further comprising at least one of Cu claim 1 , Sn claim 1 , Ni claim 1 , Ca claim 1 , Mg claim 1 , Co claim 1 , As claim 1 , Cr claim 1 , W claim 1 , Nb claim 1 , Pb claim 1 , and Ta claim 1 , which in total constitutes 0.1% or less of the composition on a mass percent basis.6. The steel sheet according to claim 1 , ...

High strength steel sheet and method for manufacturing the same

A high strength steel sheet has tensile strength of at least 1470 MPa and (tensile strength×total elongation) of at least 29000 MPa·% with a composition including, by mass %, C: 0.30% to 0.73%, Si: 3.0% or less, Al: 3.0% or less, Si+Al: at least 0.7%, Cr: 0.2% to 8.0%, Mn: 10.0% or less, Cr+Mn: at least 1.0%, P: 0.1% or less, S: 0.07% or less, N: 0.010% or less, and remainder as Fe and incidental impurities; and processing the steel sheet such that microstructure satisfies area ratio of martensite with respect to the microstructure of 15% to 90%; content of retained austenite of 10% to 50%; at least 50% of the martensite is constituted of tempered martensite and area ratio of the tempered martensite with respect to the microstructure is at least 10%; and area ratio of polygonal ferrite with respect to the microstructure is 10% or less.

HIGH STRENGTH HOT-ROLLED STEEL SHEET HAVING EXCELLENT STRETCH-FLANGE FORMABILITY AND METHOD FOR MANUFACTURING THE SAME

A high strength hot-rolled steel sheet has a composition containing more than 0.035% to 0.055% C, 0.2% or less Si, 0.35% or less Mn, 0.03% or less P, 0.03% or less S, 0.1% or less Al, 0.01% or less N, 0.08% to 0.25% Ti, and 0.0005% to 0.0035% B on a mass basis, solute B being 0.0005% or more, the remainder being Fe and unavoidable impurities; a matrix containing a ferrite phase having an area fraction of more than 95%; a microstructure in which Ti carbides having an average grain size of less than 10 nm are finely precipitated in grains of the ferrite phase and the volume fraction of the Ti carbides is 0.0015 to 0.007; and a tensile strength of 780 MPa or more. 1. A high strength hot-rolled steel sheet with excellent stretch-flange formability , having a composition comprising more than 0.035% to 0.055% C , 0.2% or less Si , 0.35% or less Mn 0.03% or less P , 0.03% or less s , 0.1% or less Al , 0.01% or less N , 0.08% to 0.25% Ti , and 0.0005% to 0.0035% B on a mass basis , solute B being 0.0005% or more , the remainder being Fe and unavoidable impurities; a matrix containing a ferrite phase having an area fraction of more than 95%; a microstructure in which Ti carbides having an average grain size of less than 10 nm are finely precipitated in grains of the ferrite phase and volume fraction of the Ti carbides is 0.0015 to 0.007; and a tensile strength of 780 MPa or more.2. The high strength hot-rolled steel sheet according to claim 1 , further comprising a plating layer on a surface of a steel sheet.3. The high strength hot-rolled steel sheet according to claim 1 , further comprising claim 1 , in total claim 1 , 1.0% or less of one or more of REMs claim 1 , Zr claim 1 , Nb claim 1 , V claim 1 , As claim 1 , Cu claim 1 , Ni claim 1 , Sn claim 1 , Pb claim 1 , Ta claim 1 , W claim 1 , Mo claim 1 , Cr claim 1 , Sb claim 1 , Mg claim 1 , Ca claim 1 , Co claim 1 , Sc claim 1 , Zn claim 1 , and Cs on a mass basis in addition to the composition.4. A method of manufacturing ...

METHOD OF HOT STAMPING GALVANIZED STEEL SHEET

In a cooling a galvanized steel sheet (W), change in emissivity of a surface of the galvanized steel sheet (W) is measured in a temperature range lower than the boiling point of zinc but not lower than the ferrite transformation temperature, using an emissivity sensor () with an observation wavelength of 1.4 μm or longer, and pressing and quenching in a pressing and quenching apparatus () is started after completion of an alloying reaction has been detected based on the change in emissivity. The emissivity sensor () preferably has an InGaAs element or a thermopile as a measuring element. 1. A method of hot stamping a galvanized steel sheet comprising:heating a galvanized steel sheet up to a temperature lower than the boiling point of zinc, and not lower than the austenite transformation temperature of the galvanized steel sheet;then, cooling the galvanized steel sheet; andthen, pressing and quenching the galvanized steel sheet,whereinin the cooling the galvanized steel sheet, change in emissivity of a surface of the galvanized steel sheet is measured in a temperature range lower than the boiling point of zinc but not lower than the ferrite transformation temperature, using an emissivity sensor with an observation wavelength of 1.4 μm or longer, andthe pressing and quenching is started upon completion of an alloying reaction detected based on the change in emissivity.2. The method of hot stamping a galvanized steel sheet according to claim 1 , wherein the emissivity of the surface of the galvanized steel sheet is continuously measured.3. The method of hot stamping a galvanized steel sheet according to claim 1 , wherein the emissivity sensor comprises an InGaAs element or a thermopile as a measuring element.4. The method of hot stamping a galvanized steel sheet according to claim 1 , wherein the measuring the change in emissivity of the surface of the galvanized steel sheet comprises:smoothing the emissivity measured using the emissivity sensor by moving averaging; ...

GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND MANUFACTURING METHOD THEREOF

A silicon steel sheet () containing Si is cold-rolled. Next, a decarburization annealing () of the silicon steel sheet () is performed so as to cause a primary recrystallization. Next, the silicon steel sheet () is coiled so as to obtain a steel sheet coil (). Next, an annealing () of the steel sheet coil () is performed through batch processing so as to cause a secondary recrystallization. Next, the steel sheet coil () is uncoiled and flattened. Between the cold-rolling and the obtaining the steel sheet coil (), a laser beam is irradiated a plurality of times at predetermined intervals on a surface of the silicon steel sheet () from one end to the other end of the silicon steel sheet () along a sheet width direction (). When the secondary recrystallization is caused, grain boundaries passing from a front surface to a rear surface of the silicon steel sheet () along paths of the laser beams are generated. 1. A manufacturing method of a grain-oriented electrical steel sheet , comprising:cold-rolling a silicon steel sheet containing Si;next, performing a decarburization annealing of the silicon steel sheet so as to cause a primary recrystallization;next, coiling the silicon steel sheet so as to obtain a steel sheet coil;next, performing an annealing of the steel sheet coil through batch processing so as to cause a secondary recrystallization; andnext, uncoiling and flattening the steel sheet coil, whereinthe manufacturing method further comprising, between the cold-rolling the silicon steel sheet containing Si and the coiling the silicon steel sheet so as to obtain the steel sheet coil, irradiating a laser beam a plurality of times at a predetermined interval in a rolling direction on a surface of the silicon steel sheet from one end to the other end of the silicon steel sheet along a sheet width direction, andwhile the secondary recrystallization is caused, grain boundaries passing from a front surface to a rear surface of the silicon steel sheet are generated along ...

Martensitic Stainless Steel and Production Method Therefor

A martensitic stainless steel for use in tableware, knives, scissors and the like, containing in % by weight, 0.10 to 0.50% carbon and 11 to 16% chromium, and a production method therefore. A production method for mid-carbon martensitic stainless steel in a strip-casting device comprising a pair of rolls rotating in opposite directions, edge dams respectively provided to both sides of the rolls so as to form a molten steel pool, and a meniscus shield for supplying inert nitrogen gas to the upper surface of the molten steel pool, wherein a stainless-steel thin sheet is produced by supplying a molten stainless steel of the above composition to the molten steel pool via a nozzle from a tundish, and a hot-rolled annealed strip is produced to a rolling reduction of 5 to 40% using in-line rollers, and relates to martensitic stainless steel produced by the production method 1. A production method for a martensitic stainless steel , wherein , in a strip-casting device comprising a pair of rolls rotating in opposite directions , edge dams respectively provided to both sides of the rolls so as to form a molten steel pool , and a meniscus shield for supplying inert nitrogen gas to the upper surface of the molten steel pool , a stainless-steel thin sheet is produced by supplying a molten stainless steel containing , as percentages by weight , 1.10 to 0.50% carbon and 11 to 16% chromium , to the molten steel pool via a nozzle from a tundish , and a hot-rolled annealed strip is produced to a rolling reduction of 5 to 40% using in-line rollers.2. The production method of claim 1 , wherein the martensitic stainless steel contains claim 1 , as percentages by weight claim 1 , 0.1 to 1.0% silicon (Si) claim 1 , 0.1 to 1.0% manganese (Mn) claim 1 , over 0 to 0.1% nickel (Ni) claim 1 , over 0 to 0.04 sulfur (S) claim 1 , and over 0 to 0.05 phosphorus (P) claim 1 , and Fe and other unavoidable impurities as remnants.3. The production method of claim 1 , wherein a hot-rolled annealed ...

Grain oriented electrical steel sheet and method for manufacturing the same

A grain oriented electrical steel sheet is subjected to magnetic domain refining treatment by electron beam irradiation and exhibits excellent low-noise properties when assembled as an actual transformer, in which a ratio (Wa/Wb) of a film thickness (Wa) of the forsierite film on a strain-introduced side of the steel sheet to a film thickness (Wb) of the forsierite film on a non-strain-introduced side of the steel sheet is 0.5 or higher, a magnetic domain discontinuous portion in a surface of the steel sheet on the strain-introduced side has an average width of 150 to 300 μm, and a magnetic domain discontinuous portion in a surface of the steel sheet on the non-strain-introduced side has an average width of 250 to 500 μm.

High-strength cold rolled sheet having excellent formability and crashworthiness and method for manufacturing the same

A high-strength cold rolled steel sheet has excellent formability and crashworthiness and includes, on a mass % basis, C: 0.05 to 0.3%, Si: 0.3 to 2.5%. Mn: 0.5 to 3.5%, P: 0.003 to 0.100%, 5: 0.02% or less, Al: 0.010 to 0.5%, the balance being iron and unavoidable impurities, the high-strength cold rolled steel sheet having a microstructure including 20% or more of ferrite on an area fraction basis, 10 to 60% of tempered martensite on an area fraction basis, 0 to 10% of martensite on an area fraction basis, and 3 to 15% of retained austenite on a volume fraction basis.

SYSTEM AND METHOD FOR TREATING AN AMORPHOUS ALLOY RIBBON

A method and a system for continuously in-line annealing a forwarding ferromagnetic amorphous alloy ribbon in a curved shape to improve its magnetic properties without causing the ribbon to become brittle and which operates at significant high ribbon feeding rates. The amorphous alloy ribbon is fed forward, tensioned and guided along a path at a preset feeding rate and is heated at a point along the path at a rate greater than 10° C./sec to a temperature to initiate a thermal treatment. Then the ribbon is initially cooled at a rate greater than 10° C./sec until the thermal treatment ends. During the thermal treatment, a series of mechanical constraints is applied on the ribbon until the amorphous alloy ribbon adopts a specific shape at rest after the thermal treatment is ended. After the initial cooling, the amorphous alloy ribbon is subsequently cooled at a sufficient rate to a temperature that will preserve the specific shape. 1. A method for treating an amorphous alloy ribbon , comprising steps of:a) feeding forward, tensioning and guiding the amorphous alloy ribbon along a path at a preset feeding rate;{'sup': '3', 'b) heating the amorphous alloy ribbon at a point along said path at a rate greater than 10° C./sec to a temperature to initiate a thermal treatment;'}{'sup': '3', 'c) cooling the amorphous alloy ribbon at a rate greater than 10° C./sec until the thermal treatment ends;'}d) applying a series of mechanical constraints on the ribbon during said thermal treatment until the amorphous alloy ribbon adopts a specific shape at rest after said thermal treatment; ande) cooling the amorphous alloy ribbon at a rate to preserve said specific shape, after said thermal treatment.25-. (canceled)6. The method according to claim 1 , wherein in step a) claim 1 , the preset feeding rate is greater than 1 m/sec.712-. (canceled)13. The method according to claim 1 , wherein:in step b) the amorphous alloy ribbon is in contact with at least one first cylinder having a first ...

Method of producing non-oriented electrical steel sheet

Disclosed is a method for producing a non-oriented magnetic steel sheet, wherein a steel slab that consists of 0.01-0.1 mass % of C, 4 mass % or less of Si, 0.05-3 mass % of Mn, 3 mass % or less of Al, 0.005 mass % or less of S, 0.005 mass % or less of N and the balance made up of Fe and unavoidable impurities is subjected to hot rolling, cold rolling and final annealing. By carrying out the final annealing, while setting the average heating rate during the heating to 100° C./sec or more and setting the soaking temperature within the temperature range of 750-1100° C., a non-oriented magnetic steel sheet that has extremely increased magnetic flux density in the rolling direction of the steel sheet is advantageously produced.

HIGH-STRENGTH STEEL SHEET AND HIGH-STRENGTH ZINC-COATED STEEL SHEET WHICH HAVE EXCELLENT DUCTILITY AND STRETCH-FLANGEABILITY AND MANUFACTURING METHOD THEREOF

This high-strength steel sheet includes by mass percentage: 0.05 to 0.4% of C; 0.1 to 2.5% of Si; 1.0 to 3.5% of Mn; 0.001 to 0.03% of P; 0.0001 to 0.01% of S; 0.001 to 2.5% of Al; 0.0001 to 0.01% of N; 0.0001 to 0.008% of O; and a remainder composed of iron and inevitable impurities, wherein a steel sheet structure contains by volume fraction 10 to 50% of a ferrite phase, 10 to 50% of a tempered martensite phase, and a remaining hard phase, wherein a 98% hardness is 1.5 or more times as high as a 2% hardness in a range from ⅛ to ⅜ of a thickness of the steel sheet, wherein a kurtosis K* of the hardness distribution between the 2% hardness and the 98% hardness is −1.2 to −0.4, and wherein an average crystal grain size in the steel sheet structure is 10 μm or less. 1. A high-strength steel sheet which has an excellent ductility and a stretch-flangeability , the steel sheet comprising by mass percentage:0.05 to 0.4% of C;0.1 to 2.5% of Si;1.0 to 3.5% of Mn;0.001 to 0.03% of P;0.0001 to 0.01% of S;0.001 to 2.5% of Al;0.0001 to 0.01% of N;0.0001 to 0.008% of O; anda remainder composed of iron and inevitable impurities,wherein a steel sheet structure contains by volume fraction 10 to 50% of a ferrite phase, 10 to 50% of a tempered martensite phase, and a remaining hard phase,wherein when a plurality of measurement regions with diameters of 1 μM or less are set in a range from ⅛ to ⅜ of a thickness of the steel sheet, hardness measurement values in the plurality of measurement regions are arranged in ascending order to obtain a hardness distribution, an integer N0.02 which is a number obtained by multiplying a total number of the hardness measurement values by 0.02 and, if present, by rounding up a decimal number, is obtained, a hardness of a measurement value which is an N0.02-th largest value from a smallest hardness measurement value is regarded as a 2% hardness, an integer N0.98 which is a number obtained by multiplying the total number of the hardness measurement ...

High strength hot rolled steel sheet having excellent bendability and method for manufacturing the same

A steel sheet including C at 0.05 to 0.15%, Si at 0.2 to 1.2%, Mn at 1.0 to 2.0%, P at not more than 0.04%, S at not more than 0.0030%, Al at 0.005 to 0.10%, N at not more than 0.005% and Ti at 0.03 to 0.13%, the balance being Fe and inevitable impurities, includes surface regions having an area fraction of bainite of less than 80% and an area fraction of a ferrite phase with a grain diameter of 2 to 15 μm of not less than 10%, the surface regions extending from both surfaces of the steel sheet each to a depth of 1.5 to 3.0% relative to a total sheet thickness, as well as an inner region other than the surface regions having an area fraction of a bainite phase of more than 95%, and has a tensile strength of not less than 780 MPa.

Method for manufacturing high-strength steel sheet parts subject in use to fatigue stresses

The manufacturing method comprises the steps of: carrying out one or more forming operations so as to give the desired geometry to the part; and subjecting the part thus formed to a single heat treatment having only a stress relieving treatment, which is preferably carried out at a temperature in the range from 530° C. to 580° C. for a time in the interval from 45 to 60 minutes and is followed by cooling of the part in air. By virtue of the formed part being subjected to a stress relieving heat treatment, the residual stress state due to the initial forming process and to the bead welding, if any, is eliminated or at least significantly reduced.

Ferritic stainless steel sheet excellent in heat resistance and workability and method of production of same

The present invention provides ferritic stainless steel sheet which is excellent in heat resistance at 950° C. and workability at ordinary temperature, that is, ferritic stainless steel sheet excellent in heat resistance and workability which is characterized by containing, by mass %, C: 0.02% or less, N: 0.02% or less, Si: over 0.1 to 1.0%, Mn: 0.5% or less, P: 0.020 to 0.10%, Cr: 13.0 to 20.0%, Nb: 0.5 to 1.0%, Cu: 1.0 to 3.0%, Mo: 1.5 to 3.5%, W: 2.0% or less, B: 0.0001 to 0.0010%, and Al: 0.01 to 1.0% and having a balance of Fe and unavoidable impurities, where Mo+W is made 2.0 to 3.5%.

HOT-ROLLED STEEL SHEET WITH EXCELLENT LOW-TEMPERATURE IMPACT TOUGHNESS AND MANUFACTURING METHOD THEREFOR

Disclosed are a hot-rolled steel sheet having a thickness of 6 mm or more and an excellent impact property, and a manufacturing method thereof. 1. A hot-rolled steel sheet with excellent low-temperature impact toughness , the hot-rolled steel sheet comprising , in percent (%) by weight of the entire composition , C: more than 0 and 0.03% or less , Si: 0.1 to 1.0% , Mn: more than 0 and 2.0% or less , P: 0.04% or less , Cr: 1.0 to 10% , Ni: more than 0 and 1.5% or less , Ti: 0.01 to 0.5% , Cu: more than 0 and 2.0% or less , N: more than 0 and 0.03% or less , Al: 0.1% or less , the remainder of iron (Fe) and other inevitable impurities ,a value of the following Formula (1) satisfies 200 to 1,150, and {'br': None, '1001.5*C+1150.6*Mn+2000*Ni+395.6*Cu−0.7*Si−1.0*Ti−45*Cr−1.0*P−1.0*Al+1020.5*N\u2003\u2003(1)'}, 'a microstructure of the cross-section perpendicular to the rolling direction has an average grain size of 50 μm or less in which a misorientation between grains is 5° or more.'}(Here, C, Mn, Ni, Cu, Si, Ti, Cr, P, Al and N mean the content (% by weight) of each element)2. The hot-rolled steel sheet according to claim 1 , wherein the hot-rolled steel sheet has a thickness of 6.0 to 25.0 mm and −20° C. Charpy impact energy of 100 J/cmor more.3. The hot-rolled steel sheet according to claim 1 , wherein the value of Formula (1) satisfies 200 to 700.4. The hot-rolled steel sheet according to claim 1 , wherein the hot-rolled steel sheet satisfies the following Formula (2).{'br': None, 'Ti/(C+N)≥10.0\u2003\u2003(2)'}5. The hot-rolled steel sheet according to claim 1 , wherein the microstructure has an average grain size of 70 μm or less in which a misorientation between grains is 15 to 180°.6. The hot-rolled steel sheet according to claim 1 , wherein the microstructure has an average grain size of 50 μm or less in which a misorientation between grains is 5 to 180°.7. The hot-rolled steel sheet according to claim 1 , wherein the microstructure has an average grain size of ...

APPARATUS FOR MANUFACTURING THIN STEEL SHEET AND METHOD FOR MANUFACTURING THIN STEEL SHEET

Using an apparatus for manufacturing a thin steel sheet including the followings which are arranged in order: a continuous casting machine () for a thin slab having a slab thickness of 70 mm to 120 mm at a lower end of a mold; a holding furnace () that is configured to maintain a temperature of a cast slab () and/or heats the cast slab (); and a rolling stand () by which finish rolling is performed, the casting speed of the thin slab is set to 4 to 7 m/min, the slab () is reduced at a rolling reduction of 30% or more by the reduction roll () after solidification is completed and when a center temperature of the slab is 1300° C. or higher, and the slab () is held at a temperature of 1150° C. or higher and 1300° C. or lower for five minutes or longer in the holding furnace (). 16-. (canceled)7. An apparatus for manufacturing a thin steel sheet , with which continuous casting , passing-through a holding furnace , and finish rolling are able to be continuously performed without cutting a slab , the apparatus comprising the followings which are arranged in order:a continuous casting machine for a thin slab having a slab thickness of 70 mm to 120 mm at a lower end of a mold;the holding furnace that is configured to maintain a temperature of a cast slab and/or heats the cast slab; anda rolling stand by which finish rolling is performed,wherein the apparatus has a reduction roll on a downstream side of a solidification completion position of the slab in the continuous casting machine, andthe slab is able to be reduced by the reduction roll.8. The apparatus for manufacturing a thin steel sheet according to claim 7 ,wherein the holding furnace is one of a furnace in which the slab passes through an atmosphere kept at a high temperature and a furnace in which the slab is heated by induction heating.9. A method for manufacturing a thin steel sheet using the apparatus for manufacturing a thin steel sheet according to claim 7 , the method comprising:setting a casting speed of the ...

COATED STEEL MEMBER, COATED STEEL SHEET, AND METHODS FOR PRODUCING SAME

This coated steel member includes: a steel sheet substrate having a predetermined chemical composition; and a coating formed on a surface of the steel sheet substrate and containing Al and Fe, in which the coating has a low Al content region having an Al content of 3 mass % or more and less than 30 mass % and a high Al content region formed on a side closer to a surface than the low Al content region and having an Al content of 30 mass % or more, a maximum C content of the high Al content region is 25% or less of a C content of the steel sheet substrate, a maximum C content of the low Al content region is 40% or less of the C content of the steel sheet substrate, and a maximum C content in a range from an interface between the steel sheet substrate and the coating to a depth of 10 μm on a side of the steel sheet substrate is 80% or less of the C content of the steel sheet substrate. 1. A coated steel member comprising: C: 0.25% to 0.65%,', 'Si: 0.10% to 2.00%,', 'Mn: 0.30% to 3.00%,', 'P: 0.050% or less,', 'S: 0.0100% or less,', 'N: 0.010% or less,', 'Ti: 0.010% to 0.100%,', 'B: 0.0005% to 0.0100%,', 'Nb: 0.02% to 0.10%,', 'Mo: 0% to 1.00%,', 'Cu: 0% to 1.00%,', 'Cr: 0% to 1.00%,', 'Ni: 0% to 1.00%,', 'V: 0% to 1.00%,', 'Ca: 0% to 0.010%,', 'Al: 0% to 1.00%,', 'Sn: 0% to 1.00%,', 'W: 0% to 1.00%,', 'Sb: 0% to 1.00%,', 'REM: 0% to 0.30%, and', 'a remainder of Fe and impurities; and, 'a steel sheet substrate containing, as a chemical composition, by mass %,'}a coating formed on a surface of the steel sheet substrate and containing Al and Fe,wherein the coating has a low Al content region having an Al content of 3 mass % or more and less than 30 mass % and a high Al content region formed on a side closer to a surface than the low Al content region and having an Al content of 30 mass % or more,a maximum C content of the high Al content region is 25% or less of a C content of the steel sheet substrate,a maximum C content of the low Al content region is 40% or less of the ...

PRODUCTION METHOD FOR HIGH-STRENGTH STEEL SHEET

A production method for a high-strength steel sheet having a tensile strength TS of 780 MPa or more is provided. The production method comprises: heating a steel slab having a predetermined chemical composition; hotrolling the steel slab; coiling the hot-rolled sheet; subjecting the hot-rolled sheet to pickling treatment; holding the hot-rolled sheet in a pre-determined temperature range for predetermined time; cold rolling the hot-rolled sheet to obtain a cold-rolled sheet; subjecting the cold-rolled sheet to first annealing treatment; cooling the cold-rolled sheet at a pre-determined average cooling rate; cooling the cold-rolled sheet to room temperature; reheating the clod-rolled sheet to perform second annealing treatment; cooling the cold-rolled sheet at a first average cooling rate; cooling the cold-rolled sheet at a second average cooling rate; reheating the cold-rolled sheet to a predetermined reheating temperature range; and holding the cold-rolled sheet in the reheating temperature range. 1. A production method for a high-strength steel sheet having a tensile strength TS of 780 MPa or more , the production method comprising: C: 0.08% or more and 0.35% or less,', 'Si: 0.50% or more and 2.50% or less,', 'Mn: 1.50% or more and 3.00% or less,', 'P: 0.001% or more and 0.100% or less,', 'S: 0.0001% or more and 0.0200% or less, and', 'N: 0.0005% or more and 0.0100% or less,', 'optionally, in mass %, at least one element selected from the group consisting of', 'Al: 0.01% or more and 1.00% or less,', 'Ti: 0.005% or more and 0.100% or less,', 'Nb: 0.005% or more and 0.100% or less,', 'V: 0.005% or more and 0.100% or less,', 'B: 0.0001% or more and 0.0050% or less,', 'Cr: 0.05% or more and 1.00% or less,', 'Cu: 0.05% or more and 1.00% or less,', 'Sb: 0.0020% or more and 0.2000% or less,', 'Sn: 0.0020% or more and 0.2000% or less,', 'Ta: 0.0010% or more and 0.1000% or less,', 'Ca: 0.0003% or more and 0.0050% or less,', 'Mg: 0.0003% or more and 0.0050% or less, and', ' ...

ULTRAHIGH-STRENGTH STEEL FOR WELDING STRUCTURE WITH EXCELLENT TOUGHNESS IN WELDING HEAT-AFFECTED ZONES THEREOF, AND METHOD FOR MANUFACTURING SAME

Provided is a ultrahigh strength steel for a welded structure having superior toughness in a weld heat-affected zone (HAZ) comprising: by wt %, carbon (C): 0.05% to 0.15%, silicon (Si): 0.1% to 0.6%, manganese (Mn): 1.5% to 3.0%, nickel (Ni): 0.1% to 0.5%, molybdenum (Mo): 0.1% to 0.5%, chromium (Cr): 0.1% to 1.0%, copper (Cu): 0.1% to 0.4%, titanium (Ti): 0.005% to 0.1%, niobium (Nb): 0.01% to 0.03%, boron (B): 0.0003% to 0.004%, aluminum (Al): 0.005% to 0.1%, nitrogen (N): 0.001% to 0.006%, phosphorus (P): 0.015% or less, sulfur (S): 0.015% or less, iron (Fe) as a residual component thereof, and inevitable impurities. 1. A ultrahigh strength steel for a welded structure having superior toughness in a weld heat-affected zone (HAZ) comprising:by wt %, carbon (C): 0.05% to 0.15%, silicon (Si): 0.1% to 0.6%, manganese (Mn): 1.5% to 3.0%, nickel (Ni): 0.1% to 0.5%, molybdenum (Mo): 0.1% to 0.5%, chromium (Cr): 0.1% to 1.0%, copper (Cu): 0.1% to 0.4%, titanium (Ti): 0.005% to 0.1%, niobium (Nb): 0.01% to 0.03%, boron (B): 0.0003% to 0.004%, aluminum (Al): 0.005% to 0.1%, nitrogen (N): 0.001% to 0.006%, phosphorus (P): 0.015% or less, sulfur (S): 0.015% or less, iron (Fe) as a residual component thereof, and inevitable impurities,wherein the Ti and N component contents satisfy Formula 1 below, the N and B component contents satisfy Formula 2 below, and the Mn, Cr, Mo, Ni, and Nb component contents satisfy Formula 3 below; and [{'br': None, '3.5≦Ti/N≦7.0 \u2003\u2003[Formula 1]'}, {'br': None, '1.5≦N/B≦4.0 \u2003\u2003[Formula 2]'}, {'br': None, '4.0 2≦Mn+Cr+Mo+Ni+3Nb≦7.0 \u2003\u2003[Formula 3]'}], 'a microstructure including, by area fraction, acicular ferrite in an amount of 30% to 40% and bainite in an amount of 60% to 70%,'}wherein in the Formulas 1 to 3, respective component units are wt %.2. The ultrahigh strength steel for a welded structure having superior toughness in a weld HAZ of claim 1 , wherein the steel further comprises claim 1 , by wt % claim 1 , one or ...

FERRITIC LIGHTWEIGHT STEEL SHEET HAVING EXCELLENT STRENGTH AND DUCTILITY AND METHOD FOR MANUFACTURING THE SAME

A ferritic steel sheet according to an exemplary embodiment of the present invention includes C at 0.01 to 0.3 wt %, Mn at 0.5 to 8 wt %, Al at 5 to 12 wt %, and Nb at 0.015 to 0.2 wt % based on an entire composition of 100 wt %, and a remaining part of Fe and an impurity. 1. A ferritic steel sheet including C at 0.01 to 0.3 wt % , Mn at 0.5 to 8 wt % , Al at 5 to 12 wt % , and Nb at 0.015 to 0.2 wt % based on an entire composition of 100 wt % , and a remaining part of Fe and an impurity ,wherein an average grain size of a ferrite crystal existing in the steel sheet is 30 μm or less.2. The ferritic steel sheet of claim 1 , wherein:the average grain size of the ferrite crystal is 15 μm or less.3. The ferritic steel sheet of claim 1 , wherein:the ferritic steel sheet includes Si at 0.04 to 2.0 wt %, Cr at 2.0 wt % or less (0% is not included), Mo at 1.0 wt % or less (0% is not included), Ni at 1.0 wt % or less (0% is not included), Ti at 0.1 wt % or less (0% is not included), V at 0.2 wt % or less (0% is not included), B at 0.01 wt % or less (0% is not included), Zr at 0.2 wt % or less (0% is not included), or a combination thereof based on the entire composition of 100 wt %.4. The ferritic steel sheet of claim 1 , wherein:a κ-carbide of a spherical shape, an oval shape, an acicular shape, or a band shape existing inside the ferritic steel sheet is included.5. The ferritic steel sheet of claim 4 , wherein:the κ-carbide at 1 to 10 vol % is included based on the entire 100 vol % of the steel sheet.6. The ferritic steel sheet of claim 4 , wherein:a particle size of the κ-carbide is in a range of 20 nm to 10 μm, and{'sup': 3', '6', '2, 'the κ-carbide is present in the range of 5×10to 1×10particles per unit area (mm).'}7. The ferritic steel sheet of claim 1 , wherein:a NbC compound existing inside the ferritic steel sheet is included.8. The ferritic steel sheet of claim 7 , wherein:the NbC compound at 0.1 to 1 vol % is included based on the entire 100 vol % of the steel ...

HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME

Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 30% or more of a ferrite phase, 40% to 65% of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 40% to 55% and the total area ratio of a bainite phase having a grain diameter of more than 5 μm and/or a martensite phase having a grain diameter of more than 5 μm is 20% or less, and a tensile strength is 980 MPa or more. 1. A high-strength steel sheet havinga chemical composition containing, by mass %, C: 0.070% to 0.100%, Si: 0.30% to 0.70%, Mn: 2.20% to 2.80%, P: 0.025% or less, S: 0.0020% or less, Al: 0.020% to 0.060%, N: 0.0050% or less, Nb: 0.010% to 0.060%, Ti: 0.010% to 0.030%, B: 0.0005% to 0.0030%, Ca: 0.0015% or less, and the balance being Fe and inevitable impurities;a microstructure including, in terms of area ratio, 30% or more of a ferrite phase, 40% to 65% of a bainite phase and/or a martensite phase, and 5% or less of cementite,wherein, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 40% to 55% and the total area ratio of a bainite phase having a grain diameter of more than 5 μm and/or a martensite phase having a grain diameter of more than 5 μm is 20% or less; anda tensile strength being 980 MPa or more.2. The high-strength steel sheet according to wherein the chemical composition further contains at least one element selected from at least one group consisting of claim 1 , by mass % claim 1 ,group I: Sb: 0.005% to 0.015%,grow:, II: one or more elements selected from Cr: 0.30% or less, V: 0.10% or less, Mo: 0.20% or less, Cu: 0.10% or less, and Ni: 0.10% ...

HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME

Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 25% or less of a ferrite phase, 75% or more of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 5% to 20%, and a tensile strength is 1180 MPa or more. 1. A high-strength steel sheet havinga chemical composition containing, by mass %, C: 0.100% to 0.150%, Si: 0.30% to 0.70%, Mn: 2.20% to 2.80%, P: 0.025% or less, S: 0.0020% or less, Al: 0.020% to 0.060%, N: 0.0050% or less, Nb: 0.010% to 0.060%, Ti: 0.010% to 0.030%, B: 0.0005% to 0.0030%, Sb: 0.005% to 0.015%, Ca: 0.0015% or less, and the balance being Fe and inevitable impurities,a microstructure including, in terms of area ratio, 25% or less of a ferrite phase, 75% or more of a bainite phase and/or a martensite phase, and 5% or less of cementite,wherein, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 5% to 20%, anda tensile strength being 1180 MPa or more.2. The high-strength steel sheet according to claim 1 , wherein the chemical composition further contains at least one element selected from at least one group consisting of claim 1 , by mass % claim 1 ,Group I: one or more elements selected from Cr: 0.30% or less V: 0.10% or less Mo: 0.20% or less, Cu: 0.10% or less, and Ni: 0.10% or less, andGroup II: REM: 0.0010% to 0.0050%.3. The high-strength steel sheet according to claim 1 , the steel sheet further having a YR of 0.85 or less.4. The high-strength steel sheet according to claim 2 , the steel sheet further having a YR of 0.85 or less.5. A method for manufacturing a high-strength steel sheet having a tensile ...

FERRITIC STAINLESS STEEL SHEET, HOT COIL, AND AUTOMOBILE EXHAUST FLANGE MEMBER

A ferritic stainless steel plate having a sheet thickness t of 5.0 to 12.0 mm, including a chemical composition consisting of, in mass percent, C: 0.001 to 0.010%, Si: 0.01 to 1.0%, Mn: 0.01 to 1.0%, P: 0.04% or less, S: 0.010% or less, Cr: 10.0 to 20.0%, Ni: 0.01 to 1.0%, Ti: 0.10 to 0.30%, V: 0.01 to 0.40%, Al: 0.005 to 0.3%, N: 0.001 to 0.02%, and as necessary, one or more of B, Mo, Cu, Mg, Sn, Sb, Zr, Ta, Nb, Hf, W, Co, Ca, REM, and Ga, with the balance being Fe and unavoidable impurities, wherein in a steel micro-structure, on a cross section parallel to a rolling direction, an area ratio of structures each satisfying: major grain diameter/minor grain diameter being 5.0 or more is 90% or more, and an average minor grain diameter of the structures is 100 μm or less. The ferritic stainless steel is excellent in toughness and suitable for an automobile exhaust flange member and the like. 1. A ferritic stainless steel sheet having a sheet thickness t of 5.0 to 12.0 mm , comprisinga chemical composition consisting of, in mass percent:C: 0.001 to 0.010%;Si: 0.01 to 1.0%;Mn: 0.01 to 1.0%;P: 0.04% or less;S: 0.010% or less;Cr: 10.0 to 20.0%;Ni: 0.01 to 1.0%;Ti: 0.10 to 0.30%;V: 0.01 to 0.40%;Al: 0.005 to 0.3%;N: 0.001 to 0.02%;B: 0 to 0.0030%;Mo: 0 to 2.0%;Cu: 0 to 0.3%;Mg: 0 to 0.0030%;Sn: 0 to 0.1%;Sb: 0 to 0.1%;Zr: 0 to 0.1%;Ta: 0 to 0.1%;Nb: 0 to 0.1%;Hf: 0 to 0.1%;W: 0 to 0.1%;Co: 0 to 0.2%;Ca: 0 to 0.0030%;REM: 0 to 0.05%; andGa: 0 to 0.1%,with the balance being Fe and unavoidable impurities, whereinin a steel micro-structure, on a cross section parallel to a rolling direction, an area ratio of structures each satisfying: major grain diameter/minor grain diameter being 5.0 or more is 90% or more, and an average minor grain diameter of the structures is 100 μm or less.2. A hot coil made of the ferritic stainless steel sheet according to .3. An automobile exhaust flange member made of the ferritic stainless steel sheet according to .4. An automobile exhaust flange ...

STEEL SHEET, PLATED STEEL SHEET, AND METHOD FOR PRODUCING THE SAME

A steel sheet includes, by mass %: C: 0.020% to 0.080%; Si: 0.01% to 0.10%; Mn: 0.80% to 1.80%; and Al: more than 0.10% and less than 0.40%; and further includes: Nb: 0.005% to 0.095%; and Ti: 0.005% to 0.095%, in which a total amount of Nb and Ti is 0.030% to 0.100%, and the steel sheet includes, as a metallographic structure, ferrite, bainite, and other phases, an area fraction of the ferrite is 80% to 95%, an area fraction of the bainite is 5% to 20%, a total fraction of the other phases is less than 3%, a tensile strength is 590 MPa or more, and a fatigue strength ratio as a fatigue strength to the tensile strength is 0.45 or more. 1. A steel sheet comprising , by mass %:C, 0.020% or more and 0.080% or less;Si: 0.01% or more and 0.10% or less;Mn: 0.80% or more and 1.80% or less;Al: more than 0.10% and less than 0.40%;Mo: 0% or more and 1.000% or less;W: 0% or more and 1.000% or less;V: 0% or more and 1.000% or less;B: 0% or more and 0.0100% or less;Ni: 0% or more and 1.50% or less;Cu: 0% or more and 1.50% or less;Cr: 0% or more and 1.50% or less;P: limited to 0.0100% or less;S: limited to 0.0150% or less;N: limited to 0.0100% or less;Nb: 0.005% or more and 0.095% or less;Ti: 0.005% or more and 0.095% or less; anda balance consisting of Fe and unavoidable impurities, whereina total amount of Nb and Ti is 0.030% or more and 0.100% or less,a metallographic structure of the steel sheet includes ferrite, bainite, and other phases,the other phases include a pearlite, a residual austenite, and a martensite,an area fraction of the ferrite is 80% or more and 95% or less,an area fraction of the bainite is 5% or more and 20% or less,a total fraction of the other phases is less than 3%,an equivalent circle diameter of a cementite in the ferrite is 0.003 μm or more and 0.300 μm or less,{'sup': 2', '2, 'a number density of the cementite in the ferrite is 0.02 particles/μmor more and 0.10 particles/μmor less,'}a tensile strength is 590 MPa or more, anda fatigue strength ratio ...

COLD ROLLED STEEL SHEET AND A METHOD OF MANUFACTURING THEREOF

A cold rolled heat treated steel sheet having a composition with the following elements, expressed in percentage by weight 0.1%≤Carbon≤0.5%, 1%≤Manganese≤3.4%, 0.5%≤Silicon≤2.5%, 0.03%≤Aluminum≤1.5%, 0%≤Sulfur≤0.003%, 0.002%≤Phosphorus≤0.02%, 0%≤Nitrogen≤0.01% and can contain one or more of the following optional elements 0.05%≤Chromium≤1%, 0.001%≤Molybdenum≤0.5%, 0.001%≤Niobium≤0.1%, 0.001%≤Titanium≤0.1%, 0.01%≤Copper≤2%, 0.01%≤Nickel≤3%, 0.0001%≤Calcium≤0.005%, 0%≤Vanadium≤0.1%, 0%≤Boron≤0.003%, 0%≤Cerium≤0.1%, 0%≤Magnesium≤0.010%, 0%≤Zirconium≤0.010%, the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet having in area fraction, 10 to 30% Residual Austenite, 50 to 85% Bainite, 1 to 20% Quenched Martensite, and less than 30% Tempered Martensite. 117.-. (canceled)18. A cold rolled heat treated steel sheet having a composition comprising the following elements , expressed in percentage by weight:0.1%≤Carbon≤0.5%1%≤Manganese≤3.4%0.5%≤Silicon≤2.5%0.03%≤Aluminum≤1.5%0%≤Sulfur≤0.003%.0.002%≤Phosphorus≤0.02%0%≤Nitrogen≤0.01%and optionally containing one or more of the following elements0.05%≤Chromium≤1%0.001%≤Molybdenum≤0.5%0.001%≤Niobium≤0.1%0.001%≤Titanium≤0.1%0.01%≤Copper≤2%0.01%≤Nickel≤3%0.0001%≤Calcium≤0.005%0%≤Vanadium≤0.1%0%≤Boron≤0.003%0%≤Cerium 0.1%0%≤Magnesium≤0.010%0%≤Zirconium≤0.010%a remainder being iron and unavoidable impurities caused by processing;a microstructure of the cold rolled heat treated steel sheet comprising in area fraction, 10 to 30% Residual Austenite, 50 to 85% Bainite, 1 to 20% Quenched Martensite, and less than 30% Tempered Martensite.19. The cold rolled heat treated steel as recited in wherein the composition includes 0.7% to 2.4% of Silicon.20. The cold rolled heat treated steel as recited in wherein the composition includes 0.03% to 0.9% of Aluminum.21. The cold rolled heat treated steel as recited in wherein the composition includes 0.03% to 0.6% of ...

High-strength steel sheet with excellent ductility and hole-expandability

A steel sheet including, in mass %, C: 0.05% or more and 0.30% or less, Si: 0.05% or more and 6.00% or less, Mn: 1.50% or more and 10.00% or less, and the balance: Fe and impurities, a steel sheet structure is composed of, in area ratio, 15% or more and 80% or less of ferrite and 20% or more and 85% or less in total of a hard structure composed of any one of bainite, martensite, or retained austenite, or any combination thereof, and to a steel sheet thickness t, an area ratio of a maximum coupled ferrite region in a region from a t/2 position at the steel sheet thickness center to a position at a depth of 3t/8 from a surface is 80% or more in area ratio to a total ferrite area, and a two-dimensional isoperimetric constant of the maximum coupled ferrite region is 0.35 or less.

NEW DUPLEX STAINLESS STEEL

The present disclosure relates to a duplex stainless steel comprising in weight % (wt %): C less than 0.03; Si less than 0.60; Mn 0.40 to 2.00; P less than 0.04; S less than or equal to 0.01; Cr more than 30.00 to 33.00; Ni 6.00 to 10.00; Mo 1.30 to 2.90; N 0.15 to 0.28; Cu 0.60 to 2.20; Al less than 0.05; balance Fe and unavoidable impurities. The present disclosure also relates to a component or a construction material comprising the duplex stainless steel. Additionally, the present disclosure also relates to a process for manufacturing a component comprising said duplex stainless steel. 2. The duplex stainless steel according to claim 1 , wherein said duplex stainless steel has a PRE claim 1 , which is greater than or equal to 36 and wherein PRE=wt % Cr+3.3*wt % Mo.3. The duplex stainless steel according to claim 1 , wherein the content of Al is less than 0.03 wt %.4. The duplex stainless steel according to claim 1 , wherein the content of Si is less than 0.30 wt %.5. The duplex stainless steel according to claim 1 , wherein the content of Mn is 0.60-1.80 wt %.6. The duplex stainless steel according to claim 1 , wherein the content of Ni is 6.50-9.50 wt %.7. The duplex stainless steel according to claim 1 , wherein the content of Cu is 1.10-1.90 wt %.8. The duplex stainless steel according to claim 1 , wherein the content of N is 0.17-0.25 wt %.9. The duplex stainless steel according to claim 1 , wherein the content of Cr is 30.50-32.50 wt %.10. The duplex stainless steel according to claim 1 , wherein the content of Mo is 1.35-2.90 wt %.11. A method for manufacturing a component comprising a duplex stainless steel claim 1 , the method comprising the following steps:{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'providing a melt comprising an alloy composition according to ;'}casting the melt to an object;optionally heat-treating the object;hot working the object to a component;heat-treating the component;optionally cold working the component; andoptionally ...

A CHEMICAL METHOD TO DECREASE OXIDE SCALE GENERATION IN HOT ROLLING

The present invention is drawn to a protective coating composition for a metallic substrate and a ceramic film coating layer formed thereon. 1. A protective coating for a metallic substrate to reduce oxide scale formation during hot working , the protective coating comprising at least one high melting point inorganic material presented in an amount raging from about 30.0 wt. % to about 90.0 wt. % , and at least one silicate presented in an amount ranging from about 0.5 wt. % to about 30.0 wt. % , wherein the wt. % is measured by the total weight of the protective coating composition.2. The protective coating of claim 1 , wherein the at least one high melting point inorganic material is selected from the group consisting of a carbide claim 1 , a nitride claim 1 , a boride claim 1 , a metal oxide claim 1 , composite materials thereof and combinations thereof.3. The protective coating of claim 1 , wherein the at least one high melting point inorganic material is selected from the group consisting of calcinized aluminum oxide claim 1 , zirconium silicate (ZrO.SiO claim 1 , Zircopax™) claim 1 , a mixture of zirconium silicate and silica (Zircopax Plus™) claim 1 , zirconium oxide (ZrO) claim 1 , silicon carbide claim 1 , and combinations thereof.4. The protective coating of claim 3 , wherein the at least one high melting point inorganic material is a combination of zirconium silicate claim 3 , silica and silicon carbide claim 3 , or a combination of calcined aluminum oxide and silicon carbide.5. The protective coating composition of claim 1 , wherein the at least one high melting point inorganic material has a median particle size ranging from about 5 μm to about 44 μm.6. The protective coating composition of claim 1 , wherein the at least one high melting point inorganic material is present in an amount range selected from: about 30.0 wt. % to about 40.0 wt. % claim 1 , about 30.0 wt. % to about 50.0 wt. % claim 1 , about 30.0 wt. % to about 60.0 wt. % claim 1 , about 30 ...

ULTRA-HIGH STRENGTH STEEL SHEET HAVING EXCELLENT PHOSPHATABILITY AND BENDABILITY AND METHOD FOR MANUFACTURING SAME

Provided is an ultra-high strength steel sheet having excellent phosphatability and bendability. The ultra-high strength steel sheet includes, by weight percentage (wt %), carbon (C): 0.08% to 0.2%, silicon (Si): 0.05% to 1.3%, manganese (Mn): 2.0% to 3.0%, phosphorus (P): 0.001% to 0.10%, sulfur (S): 0.010% or less, aluminum (Al): 0.01% to 0.1%, chromium (Cr): 0.3% to 1.2%, boron (B): 0.0010% to 0.0030%, titanium (Ti): 0.01% to 0.05%, nitrogen (N): 0.001% to 0.01%, a remainder of iron (Fe) and other inevitable impurities, satisfying: 3.4≤Ti/N≤10, 1.0≤Mn/(Si+Cr), and 0.7≤Mn*/(Si*+Cr*)≤Mn/(Si+Cr), where Ti, N, Mn, Si and Cr refer to a weight percentage (wt %), and Mn*, Si* and Cr* refer to an average of values obtained by GDS component analysis from a surface to a 0.1 μm position in a thickness direction. 1. An ultra-high strength steel sheet having excellent phosphatability and bendability , comprising , by weight percentage (wt %) , carbon (C): 0.08% to 0.2% , silicon (Si): 0.05% to 1.3% , manganese (Mn): 2.0% to 3.0% , phosphorus (P): 0.001% to 0.10% , sulfur (S): 0.010% or less , aluminum (Al): 0.01% to 0.1% , chromium (Cr): 0.3% to 1.2% , boron (B): 0.0010% to 0.0030% , titanium (Ti): 0.01% to 0.05% , nitrogen (N): 0.001% to 0.01% , a remainder of iron (Fe) and other inevitable impurities ,wherein Ti and N satisfy Relationship 1,wherein Mn, Si and Cr satisfy Relationship 2, [{'br': None, '3.4≤Ti/N≤10 \u2003\u2003[Relationship 1]'}, {'br': None, '1.0≤Mn/(Si+Cr) \u2003\u2003[Relationship 2]'}, {'br': None, '0.7≤Mn*/(Si*+Cr*)≤Mn/(Si+Cr) \u2003\u2003[Relationship 3]'}], 'wherein amounts of Mn, Si and Cr in a surface layer, ranging from a surface to a 0.1 pm position in a thickness direction, satisfy Relationship 3wherein each of Ti, N, Mn, Si and Cr in Relationships 1 to 3 refers to a weight percentage (wt %) of the element, and each of Mn*, Si* and Cr* in Relationship 3 refers to an average of values obtained by GDS component analysis from a surface to a 0.1 pm ...

Retention Of Mechanical Properties In Steel Alloys After Processing And In The Presence Of Stress Concentration Sites

This invention is related to retention of mechanical properties in high strength steel at reduced thicknesses and which mechanical property performance is also retained at relatively high strain rates. These new steels can offer advantages for a myriad of applications where reduced sheet thickness is desirable. In addition, the alloys herein are those that retain useful mechanical properties after introduction of a geometric discontinuity and an accompanying stress concentration. 1. A method to retain mechanical properties in a metallic sheet alloy at reduced thickness comprising:a. supplying a metal alloy comprising at least 70 atomic % iron and at least four or more elements selected from Si, Mn, Cr, Ni, Cu, or C, melting said alloy, cooling at a rate of <250 K/s, and solidifying to a thickness of 25.0 mm up to 500 mm;{'sub': 1', '1', '1', '1, 'b. processing said alloy into sheet form with thickness Twith the sheet having a total elongation of X(%), an ultimate tensile strength of Y(MPa), and a yield strength of Z(MPa);'}{'sub': 2', '1', '2', '1', '2', '1', '2', '1, 'c. further processing said alloy into a second sheet with reduction in thickness T Подробнее

Vehicle part having high strength and excellent durability, and manufacturing method therefor

Provided are a part for vehicle having high strength and excellent durability, and a manufacturing method therefor. The part for vehicle comprises, by a weight ratio, a composition comprising 0.20-0.50% of C, 0.5% or less of Si, 1.0-2.0% of Mn, 0.01-0.1% of Al, 0.010% or less of P, 0.003% or less of S, 0.01-0.1% of Ti, 0.05-0.5% of Cr, 0.05-0.3% of Mo, 0.01% or less of N, and the remainder being Fe and other inevitable impurities, and the part for vehicle can have, by an area ratio, a microstructure comprising 90% or more of tempered martensite, 4% or less of retained austenite, and the remainder being one type or both of two types selected from among the ferrite and bainite structures.

Method for Producing a Steel Sheet Having Improved Strength, Ductility and Formability

A method for producing a steel sheet is provided. The steel sheet has a microstructure including, in area fraction, 20% to 50% intercritical ferrite, 10% to 20% retained austenite, 25% to 45% tempered martensite, 10% to 20% fresh martensite, and bainite. The sum of tempered martensite and bainite is between 30% and 60%. The method includes providing a cold-rolled steel sheet including, in weight percent, 0.18%≤C≤0.25%, 0.9%≤Si≤1.8%, 0.02%≤Al≤1.0%, with 1.00%≤Si+Al≤2.35%, 1.5%≤Mn 2.5%, 0.010%≤Nb≤0.035%, 0.10%≤Cr≤0.40%, and a remainder including Fe and unavoidable impurities. The method further includes annealing the steel sheet to obtain 50% to 80% austenite and 20% to 50% of ferrite, quenching the sheet at a cooling rate between 20° C./s and 50° C./s to a quenching temperature between Ms-50° C. and Ms-5° C., heating the sheet to a partitioning temperature between 375° C. and 450° C. and maintaining the sheet at the partitioning temperature for at least 50 s, then immediately cooling the sheet to room temperature. A steel sheet is also provided. 121-. (canceled)23. The method according to claim 22 , wherein the steel sheet has claim 22 , just after quenching a structure consisting of claim 22 , in area fraction claim 22 , at least 20% austenite claim 22 , between 30% and 60% martensite claim 22 , and between 20% and 50% ferrite.24. The method according to claim 22 , wherein the chemical composition of the steel includes 1.25%≤Si+Al≤2.35%.25. The method according to claim 22 , further comprising a step of:hot dip coating the steel sheet between the step of maintaining the steel sheet at the partitioning temperature PT and the step of cooling the steel sheet down to the room temperature.26. The method according to claim 25 , wherein the partitioning temperature PT is between 400° C. and 430° C.27. The method according to claim 25 , wherein the partitioning time Pt is between 50 s and 150 s.28. The method according to claim 25 , wherein the hot dip coating step is a ...

Mn-CONTAINING GALVANNEALED STEEL SHEET AND METHOD FOR PRODUCING THE SAME

High-strength galvannealed steel sheet including any of a) an oxide containing Fe and Mn, b) an oxide containing Fe and Mn and an Fe oxide, c) an oxide containing Fe and Mn and a Mn oxide, d) an oxide containing Fe and Mn, an Fe oxide, and a Mn oxide, and e) an Fe oxide and a Mn oxide is present in a zinc coated layer. The total amount of oxide is 0.01 to 0.100 g/m; the ratio by mass % of Mn to Fe, e.g., Mn/Fe, contained in the oxide is 0.10 to 10.00; an oxide of at least one selected from Fe and Mn is present in an amount of 60% or more; and an oxide of at least one selected from Fe and Mn is present in a surface layer portion of a steel sheet in an amount of 0.040 g/mor less (not including zero). 1. A Mn-containing galvannealed steel sheet , comprising a steel sheet containing , on a mass % basis:C: 0.03% to 0.35%;Si: 0.01% to 2.00%;Mn: 3.0% to 8.0%;Al: 0.001% to 1.000%;P: 0.10% or less; and{'sup': '2', 'claim-text': 'wherein the zinc coated layer contains any one of a) to e) described below,', 'S: 0.01% or less, the balance being Fe and incidental impurities, the steel sheet having a zinc coated layer on one or both surfaces thereof with a coating weight of 20 to 120 g/m,'}a) an oxide containing Fe and Mn,b) an oxide containing Fe and Mn and an Fe oxide,c) an oxide containing Fe and Mn and a Mn oxide,d) an oxide containing Fe and Mn, an Fe oxide, and a Mn oxide, and [{'sup': '2', 'a total amount of the oxide is 0.01 to 0.100 g/min terms of an amount of O, a ratio by mass % of Mn to Fe, i.e., Mn/Fe, contained in the oxide is 0.10 to 10.00,'}, 'the oxide of at least one selected from Fe and Mn is present in an amount of 60% or more in terms of a cross-sectional area fraction in a range from a surface of the zinc coated layer to a position 50% or less of a total thickness of the zinc coated layer, and', {'sup': '2', 'an oxide of at least one selected from Fe and Mn is present in a surface layer portion of the steel sheet in an amount of 0.040 g/mor less (not ...

Method for Producing a High Strength Steel Sheet Having Improved Strength and Formability, and Obtained High Strength Steel Sheet

A method for producing a steel sheet having a microstructure including 71% to 91% martensite and bainite, 9% to 13% retained austenite, and at most 20% ferrite is provided. The method includes providing a cold-rolled steel sheet including, in weight percent: 0.13%≤C≤0.22%, 1.2%≤Si≤2.3%, 0.02%≤Al≤1.0%, with 1.25%≤Si+Al≤2.35%, 2.4%≤Mn≤3%, Ti≤0.05%, Nb≤0.05% and a remainder of Fe and unavoidable impurities, annealing the steel sheet to obtain 80% to 100% austenite and 0% to 20% ferrite, quenching the steel sheet at a cooling rate between 20° C./s and 50° C./s to a quenching temperature between 240° C. and 310° C., heating the steel sheet to a partitioning temperature between 400° C. and 465° C. and maintaining the steel sheet at the partitioning temperature for 50 to 250 seconds, then immediately cooling the sheet to room temperature. Steel sheets are also provided. 117to . (canceled)18. A method for producing a steel sheet having a microstructure consisting of between 71% and 91% of a sum of martensite and bainite , between 9% and 13% retained austenite , and at most 20% ferrite , the method comprising the following successive steps: 0.13%≤C≤0.22%,', '1.2%≤Si≤2.3%,', '0.02%≤Al≤1.0%,', 'with 1.25%≤Si+Al≤2.35%,', '2.4%≤Mn≤3%,', 'Ti≤0.05%', 'Nb≤0.05%, and, 'providing a cold-rolled steel sheet, made of a steel having a chemical composition containing by weighta remainder, the remainder including Fe and unavoidable impurities;{'sub': 'A', 'annealing the steel sheet at an annealing temperature Tso as to obtain a structure comprising from 80% to 100% austenite and from 0% to 20% ferrite;'}quenching the steel sheet at a cooling rate between 20° C./s and 50° C./s down to a quenching temperature QT between 240° C. and 270° C.;heating the steel sheet up to a partitioning temperature PT between 440° C. and 460° ;maintaining the steel sheet at the partitioning temperature PT for a partitioning time Pt between 50 s and 250 s; andimmediately after the maintaining step, cooling the ...

Method For Producing a High Strength Steel Sheet Having Improved Ductility and Formability, and Obtained Steel Sheet

A method for producing a steel sheet is provided. The method includes providing a cold-rolled steel sheet including in weight %: 0.15%≤C≤0.23%, 1.4%≤Mn≤2.6%, 0.6%≤Si≤1.5%, 0.02%≤Al≤1.0%, with 1.0%≤Si+Al≤2.0%, 0≤Nb≤0.035%, 0≤Mo≤0.3%, 0≤Cr≤0.3%, and a remainder of Fe and unavoidable impurities, annealing the steel sheet at an annealing temperature between Ac1 and Ac3 to obtaining at least 40% austenite and at least 40% intercritical ferrite, quenching the sheet from at least 600° C. at a cooling rate of at least 20° C./s to a quenching temperature between 180° C. and 260° C., heating the sheet to a partitioning temperature between 375° C. and 470° C. and maintaining the sheet at this partitioning temperature for a partitioning time Pt between 25 s and 440 s, then cooling the sheet to room temperature. A steel sheet is also provided. 133-. (canceled)34. A method for producing a steel sheet having a tensile strength of at least 980 MPa , a total elongation of at least 16% , and a hole expansion ratio HER of at least 20% ,the method for producing the steel sheet comprising the successive steps of: 0.15%≤C≤0.23%,', '1.4%≤Mn≤2.6%,', '0.6%≤Si≤1.5%,', '0.02%≤Al≤1.0%,', 'with 1.0%≤Si+Al≤2.0%,', '0≤Nb≤0.035%,', '0≤Mo≤0.3%,', '0≤Cr≤0.3%,', 'Ni<0.05%,', 'Cu<0.03%,', 'V<0.007%,', 'B<0.0010%,', 'S<0.005%,', 'P<0.02%,', 'N<0.010%, and, 'providing a cold-rolled steel sheet, made of a steel having a chemical composition including by weighta remainder, the remainder including Fe and unavoidable impurities;annealing the steel sheet at an annealing temperature TA between Ac1 and Ac3 to obtain a structure including at least 40% austenite and at least 40% intercritical ferrite;quenching the steel sheet from a temperature of at least 600° C., at a cooling rate of at least 20° C./s, down to a quenching temperature QT between 180° C. and 260° C.;heating the steel sheet up to a partitioning temperature PT between 375° C. and 470° C.;maintaining the steel sheet at the partitioning temperature ...

High-strength steel sheet and high-strength galvanized steel sheet

A high-strength steel sheet includes: a specific chemical composition; and a microstructure represented by, in a ⅛ thickness to ⅜ thickness range with ¼ thickness of a sheet thickness from a surface being a center, in volume fraction, ferrite: 85% or less, bainite: 3% or more and 95% or less, tempered martensite: 1% or more and 80% or less, retained austenite: 1% or more and 25% or less, pearlite and coarse cementite: 5% or less in total, and fresh martensite: 5% or less, in which the solid-solution carbon content in the retained austenite is 0.70 to 1.30 mass %, and to all grain boundaries of retained austenite grains having an aspect ratio of 2.50 or less and a circle-equivalent diameter of 0.80 μm or more, the proportion of interfaces with the tempered martensite or the fresh martensite is 75% or less.

HIGH-YIELD-RATIO COLD-ROLLED DUAL-PHASE STEEL AND MANUFACTURING METHOD THERFOR

Disclosed is a high-yield-ratio cold-rolled dual-phase steel, having the following chemical elements in percentage by mass: 0.05%-0.08% of C, 0.9%-1.2% of Mn, 0.1%-0.6% of Si, 0.030%4060% of Nb, 0.030%-0.060% of Ti, 0.015%-0.045% of Al, and the balance being Fe and other inevitable impurities. A manufacturing method for the high-yield-ratio cold-rolled dual-phase steel, comprising: (1) smelting and casting; (2) hot rolling, wherein a casting blank is controlled and soaked at a temperature of 1200° C.-1250° C.; rolled with the finish rolling temperature being 840° C.-930° C.; cooled at a speed of 20° C./s-70° C./s, and then wound at the winding temperature being 570° C.-630° C.; (3) cold rolling; (4) annealing at the soaking temperature being 750° C.-790° C. for 40 s-200 s, cooling at a speed of 30° C./s-80° C./s, the start temperature of cooling is 650° C. to 730° C., the aging temperature is 200° C. to 260° C., and the overaging time is 100 s to 400 s; and (5) leveling. 1. A cold-rolled dual-phase steel having a high yield ratio , comprising the following chemical elements in mass percentages:C: 0.05-0.08%, Mn: 0.9-1.2%, Si: 0.1-0.6%, Nb: 0.030-0.060%, Ti: 0.030-0.060%, Al: 0.015-0.045%, and a balance of Fe and other unavoidable impurities.2. The cold-rolled dual-phase steel having a high yield ratio according to claim 1 , wherein the steel has a microstructure which is a complex phase structure of martensite+ferrite+[NbxTiy(C claim 1 ,N)z] carbonitride.3. The cold-rolled dual-phase steel having a high yield ratio according to claim 2 , wherein the martensite has a phase proportion of 20-30% claim 2 , and the martensite is in the shape of long strips-islands.4. The cold-rolled dual-phase steel having a high yield ratio according to claim 2 , wherein the [NbxTiy(C claim 2 ,N)z] carbonitride has an irregular spherical shape and is uniformly distributed in ferrite grains claim 2 , and the [NbxTiy(C claim 2 ,N)z] carbonitride has a phase proportion of 5-10%.5. The cold ...

COLD ROLLED AND HEAT-TREATED STEEL SHEET AND METHOD OF MANUFACTURING THE SAME

A cold rolled and heat-treated steel sheet having a composition including, by weight percent: C 0.3-0.4%, Mn 2.0-2.6%, Si: 0.8-1.6%, Al 0.01-0.6%, Mo 0.15-0.5%, Cr 0.3-1.0%, Nb≤0.06%, Ti≤0.06%, Ni≤0.8%, S≤0.010%, P≤0.020% and N≤0.008%, the remainder of the composition being iron and unavoidable impurities resulting from the smelting, and having a microstructure consisting of, in surface fraction: between 15% and 30% of retained austenite, said retained austenite having a carbon content of at least 0.7%, between 70% and 85% of tempered martensite, at most 5% of fresh martensite and at most 5% of bainite. It also deals with a manufacturing method thereof. 117-. (canceled)18. A cold-rolled and heat-treated steel sheet , made of a steel having a composition comprising , by weight percent:C: 0.3-0.4%Mn: 2.0-2.6%Si: 0.8-1.6%Al: 0.01-0.6%Mo: 0.15-0.5%Cr: 0.3-1.0%Nb≤0.06%Ti≤0.06%Ni≤0.8%S≤0.010%P≤0.020%N≤0.008%Cu≤0.03%and optionally one or more of the following elements, in weight percentage:B: 0.0003-0.005%V≤0.2%a remainder of the composition being iron and unavoidable impurities resulting from processing,the steel sheet having a microstructure consisting of, in surface fraction:between 15% and 30% of retained austenite, said retained austenite having a carbon content of at least 0.7%;between 70% and 85% of tempered martensite;at most 5% of fresh martensite; andat most 5% of bainite.19. The cold-rolled and heat-treated steel sheet as recited in wherein the chromium content is between 0.6% and 0.8%.20. The cold-rolled and heat-treated steel sheet as recited in wherein the silicon content is below 1.5%.21. The cold-rolled and heat-treated steel sheet as recited in wherein the silicon content is below 1.4%.22. The cold-rolled and heat-treated steel sheet as recited in wherein the silicon content is below 1.3%.23. The cold-rolled and heat-treated steel sheet as recited in wherein the cumulated amount of silicon and aluminum is equal to or above 1.6%.24. The cold-rolled and heat ...

High-strength hot-dip galvannealed steel sheet and method for producing same

A method for producing a high-strength hot-dip galvannealed steel sheet, in which a high-strength steel sheet is used as a base material, includes a rolling step (x) of rolling a hot-dip galvannealed steel sheet with a coating layer having an Fe concentration of 8% to 17% by mass, and a heat treatment step (y) of heating the coated steel sheet which has been subjected to the rolling step (x) under the conditions satisfying the following formulae (1) and (2):(273+T)×(20+2×log10(t))≥8000  (1)40≤T≤160  (2)where T: heating temperature (° C.) of the coated steel sheet, and t: holding time (hr) at the heating temperature T.

Method for Producing Thermo-Mechanically Produced Hot-Rolled Strip Products

The invention relates to a method for producing thermomechanically produced hot strip products in which a steel alloy is melted; the steel alloy is adjusted so that a recrystallization during the hot rolling is suppressed; the final rolling temperature is greater than 800° C.; the melted steel alloy is cast into slab ingots and after being heated to a temperature above Ac, the slab ingots are hot rolled until they reach a desired degree of deformation and a desired strip thickness; after the rolling, the strip is cooled to room temperature and for hardening purposes, is briefly heated to a temperature >Ac3 and cooled again, characterized in that the heating takes place with a temperature increase of more than 5 K/s, more than 10 K/s, more than 50 K/s, or more than 100 K/s, and is kept at a desired target temperature for a period of 0.5 to 60 s before cooling to yield improved mechanical properties. 1. A method for producing thermomechanically produced hot strip products , comprising the steps of:providing a steel alloy including the following elements, in percent by weight:0.03 to 0.22% carbon,0.0 to 2.0% silicon,0.5 to 3.0% manganese,0.02 to 1.2% aluminum,0 to 2.0% chromium,0 to 2.0% nickel,0.0 to 1.0% molybdenum,0.0 to 1.5% copper,0 to 0.02% phosphorus,0 to 0.01% sulfur,0 to 0.008% nitrogen,0 to 0.005% boron,0.0 to 0.2% niobium,0.0 to 0.3% titanium,0.0 to 0.5% vanadiumthe remainder being comprised of iron and smelting-related impurities;melting the steel alloy;adjusting the steel alloy so that a recrystallization during hot rolling is suppressed;casting the melted steel alloy into slab ingots;heating the slab ingots to a temperature above Ac3,hot rolling the slab ingots using a final rolling temperature greater that 800° C. until they reach a desired degree of deformation and a desired strip thickness to form steel strips;cooling the steel strips to room temperature; andhardening the steel strips by heating the steel strips to a temperature >Ac3 and cooling them ...

PRESS HARDENED PART WITH HIGH RESISTANCE TO DELAYED FRACTURE AND A MANUFACTURING PROCESS THEREOF

A press hardened coated steel part with high resistance to delayed fracture, the coating containing (Fe—Al) intermetallic compounds resulting from the diffusion of iron into an aluminum or an aluminum-based alloy, or an aluminum alloy of a precoating, wherein the chemical composition of the steel includes, in weight: 0.16%≤C≤0.42%, 0.1%≤Mn≤3%, 0.07%≤Si≤1.60%, 0.002%≤Al≤0.070%, 0.02%≤Cr≤1.0%, 0.0005≤B≤0.005%, 0.002%≤Mg≤0.007%, 0.002%≤Ti≤0.11%, 0.0008%≤O≤0.005%, wherein (Ti)×(O)×10≤2, 0.001%≤N≤0.007%, 0.001%≤S≤0.005%, 0.001%≤P≤0.025% and optionally one or more elements selected from the list of: 0.005%≤Ni≤0.23%, 0.005%≤Nb≤0.060%, the remainder being Fe and unavoidable impurities, and wherein the microstructure includes at least 95% martensite. 119-. (canceled)20: A press hardened coated steel part with high resistance to delayed fracture , comprising a base of steel and a coating , the coating containing (Fex-Aly) intermetallic compounds resulting from the diffusion of iron into an aluminum or an aluminum-based alloy , or an aluminum alloy of a precoating , wherein the chemical composition of the steel comprises , in weight:0.16%≤C≤0.42%0.1%≤Mn≤3%0.07%≤Si≤1.60%0.002%≤Al≤0.070%0.02%≤Cr≤1.0%,0.0005≤B≤0.005%0.002%≤Mg≤0.007%0.002%≤Ti≤0.110%0.0008%≤0≤0.005%{'sup': '2', 'wherein (Ti)×(O)×107≤2'}0.001%≤N≤0.007%0.001%≤S≤0.005%0.001%≤P≤0.025%and optionally one or more elements selected from:0.005%≤Ni≤0.23%, and0.005%≤Nb≤0.060%,a remainder being Fe and unavoidable impurities,and wherein a microstructure of the steel includes at least 95% martensite.21: The press hardened coated steel part as recited in wherein 0.18%≤C≤0.35%22: The press hardened coated steel part as recited in wherein 0.55%≤Mn≤1.40%23: The press hardened coated steel part as recited in wherein Si≤0.30%24: The press hardened coated steel part as recited in wherein an average size dof oxides claim 20 , carbonitrides claim 20 , sulfides and oxisulfides is less than 1.7 μm and wherein at least one of the conditions ...

ELECTRICAL STEEL SHEET AND MANUFACTURING METHOD THEREFOR

A manufacturing method of an electrical steel sheet according to an embodiment of the present invention includes: hot-rolling a slab to manufacture a hot-rolled sheet; removing some of scales formed on the hot-rolled sheet and leaving a scale layer having a thickness of 10 nm or more; controlling roughness of the hot-rolled sheet in which the scale layer remains; cold-rolling it to manufacture a cold-rolled sheet; and annealing the cold-rolled sheet. 1. An electrical steel sheet comprising:an electrical steel sheet base substrate; anda scale layer present in an inner direction from a surface of the electrical steel sheet base substrate,wherein a thickness of the scale layer is 1 to 100 nm, andthe electrical steel sheet base substrate includes, in wt %, C at 0.1% or less, Si at 6.0% or less, P at 0.5% or less, S at 0.005% or less, Mn at 1.0% or less, Al at 2.0% or less, N at 0.005% or less, Ti at 0.005% or less, Cr at 0.5% or less, and the balance of Fe and inevitable impurities.2. The electrical steel sheet of claim 1 , whereinthe scale layer includes: Si at 5 to 80 wt %, O at 5 to 80 wt %, and the balance of Fe and inevitable impurities.3. The electrical steel sheet of claim 1 , whereinroughness of the scale layer is 0.01 to 0.5 nm.4. The electrical steel sheet of claim 1 , further comprisingan insulating coating layer positioned on the scale layer.5. A manufacturing method of an electrical steel sheet claim 1 , comprising:hot-rolling a slab to manufacture a hot-rolled sheet;removing some of scales formed on the hot-rolled sheet and leaving a scale layer having a thickness of 10 nm or more;controlling roughness of the hot-rolled sheet in which the scale layer remains;cold-rolling the hot-rolled sheet having the controlled roughness to manufacture a cold-rolled sheet; andannealing the cold-rolled sheet.6. The manufacturing method of the electrical steel sheet of claim 5 , wherein{'sup': 3', '3, 'in the leaving of the scale layer, by using a blast method, an inputted ...

Ultrathin Alloys

Herein is described a process for preparing an alloy that includes defining a product composition, thickness, and homogeneity; providing a base that has a thickness less than the product thickness and has a base composition; depositing an alloying material onto at least one surface of the base to yield a coated base that has a composition equal the product composition but has a different homogeneity; and then full thickness annealing the base and the alloying material to provide the product homogeneity. The process can be used to provide ultrathin foils, for example, ultrathin foils of ferrous or aluminum alloys. 1. (canceled)2. The process of claim 15 , wherein the product composition is selected from the group consisting of a chromium-iron alloy claim 15 , a nickel-iron alloy claim 15 , a chromium-nickel-iron alloy claim 15 , a manganese-iron alloy claim 15 , a chromium-manganese-iron alloy claim 15 , and a chromium-manganese-nickel-iron alloy.3. The process of claim 2 , wherein the product is a stainless steel.4. A process for preparing an thin claim 2 , preferably ultrathin claim 2 , ferrous-alloy or aluminum-alloy product comprising: a thickness of less than 250 μm, and', 'comprises a base composition that includes a majority (wt. %) of iron or aluminum;, 'providing a rolled iron or aluminum base that has'}depositing an alloying material onto a major surface of the base thereby providing a coated base, the coated base having a coated base thickness; and thenannealing the base and alloying material to provide the ferrous-alloy or aluminum-alloy product;wherein the process is free of any cold rolling that reduces the coated base thickness by greater than about 5%.5. The process of claim 4 , wherein the base composition includes at least 85 wt. % iron; and wherein the base composition includes less than about 10 wt. % of any one of the elements selected from the group consisting of carbon claim 4 , silicon claim 4 , boron claim 4 , aluminum claim 4 , phosphorous ...

HOT PRESS MOLDING AND MANUFACTURING METHOD THEREFOR

A hot press molding including: a first forming region exhibiting a metal structure, which contains 80-97 area % of martensite and 3-20 area % of retained austenite, respectively, and in which the residual structure is 5 area % or less; and a second forming region exhibiting a metal structure, which contains 70-97 area % of bainitic ferrite, 27 area % or less of martensite, and 3-20 area % of retained austenite, respectively, and in which the residual structure is 5 area % or less. As a result, hot press moldings, which have at least a region corresponding to a shock-resistant area and a region corresponding to an energy-absorbing area in a single molding and in which a high level of balancing of high strength with elongation according to the respective region can be achieved, are provided without using a welding method. 1. A hot press molded article formed by hot press molding of a thin steel plate , comprising:a first molding region exhibiting a metal structure which contains 80-97 area % of martensite and 3-20 area % of retained austenite and which has a residual structure at 5 area % or less; anda second molding region exhibiting a metal structure which contains 70-97 area % of bainitic ferrite, 27 area % or less of martensite, and 3-20 area % of retained austenite and which has a residual structure at 5 area % or less.2. The hot press molded article according to claim 1 , whereinthe first and second molding regions have an identical chemical component composition, and 0.15-0.3% of C,', '0.5-3% of Si,', '0.5-2% of Mn,', '0.05% or less of P,', '0.05% or less of S,', '0.01-0.1% of Al,', '0.01-1% of Cr,', '0.0002-0.01% of B,', '[N]×4-0.1% of Ti, and', '0.001-0.01% of N, where 0% is not inclusive for the P and the S, and [N] denotes an N content in units of %, and, 'steel of each component region contains, in units of mass %,'}the steel of each component region has a residual consisting of iron and an inevitable impurity.3. The hot press molded article according to ...

PROCESS FOR MANUFACTURING IRON-CARBON-MAGANESE AUSTENITIC STEEL SHEET WITH EXCELLENT RESISTANCE TO DELAYED CRACKING

A process for fabricating a steel sheet is provided. The process includes soaking a steel sheet. The steel has a composition including iron, carbon, manganese, silicon, aluminum, sulfur, phosphorus and nitrogen and at least one metallic element X chosen among vanadium, titanium, niobium, molybdenum, and chromium. A quantity Xof metallic element under the form of carbides, nitrides or carbonitrides is, by weight: 1. A process for fabricating a steel sheet , comprising: [{'br': None, '0.35≦C≦1.05%;'}, {'br': None, '15%≦Mn≦26%;'}, {'br': None, 'Si≦3%;'}, {'br': None, 'Al≦0.050%;'}, {'br': None, 'S≦0.030%;'}, {'br': None, 'P≦0.080%;'}, {'br': None, 'N≦0.1%;'}], 'soaking a steel sheet, comprising a steel with a composition comprising Fe, and by weight [{'br': None, '0.050%≦V≦0.50%,'}, {'br': None, '0.040%≦Ti≦0.50%,'}, {'br': None, '0.070%≦Nb≦0.50%,'}, {'br': None, '0.14%≦Mo≦2%; and'}, {'br': None, '0.070%≦Cr≦2%;'}], 'at least one metallic element X chosen among vanadium, titanium, niobium, molybdenum, and chromium, in a percentage as follows{'sub': 'p', 'claim-text': [{'br': None, 'sub': 'p', '0.030%≦V≦0.40%'}, {'br': None, 'sub': 'p', '0.030%≦Ti≦0.50%'}, {'br': None, 'sub': 'p≦', '0.040%≦Nb0.40%'}, {'br': None, 'sub': 'p', '0.14%≦Mo≦0.44%'}, {'br': None, 'sub': 'p', '0.070%≦Cr≦0.6%,'}], 'wherein a quantity Xof metallic element under the form of carbides, nitrides or carbonitrides is, by weightunder a pure nitrogen or argon atmosphere with a dew point lower than −30° C. at a soaking temperature θ comprised between 250 and 900° C., with a dynamic circulation of a regenerated atmosphere.2. The process of claim 1 , wherein the steel sheet comprises a Zn or Zn—Y alloy coating claim 1 , wherein element Y is at least one element selected from the group consisting of consisting of Ni claim 1 , Cr claim 1 , and Mg and wherein the temperature and time of the soaking satisfy θ(° C.)Ln(t(s))≧2200.3. The process of claim 2 , wherein θ (° C.)Ln(t(s))≧2450.4. The process of claim 2 , ...

Iron-carbon-manganese austenitic steel sheet with excellent resistance to delayed cracking

An austenitic steel sheet excellent in resistance to delayed cracking is provided. The composition of said steel comprises in weight: 0.35%≦C≦1.05% 15%≦Mn≦26% Si≦3% Al≦0.050% S≦0.030% P≦0.080% N≦0.1%, at least one metallic element X chosen among vanadium, titanium, niobium, molybdenum, chromium 0.050%≦V≦0.50%, 0.040%≦Ti≦0.50% 0.070%≦Nb≦0.50% 0.14%≦Mo≦2% 0.070%≦Cr≦2%. The composition may optionally include B, Ni and/or Cu. The remainder of the composition includes iron and unavoidable impurities inherent to fabrication, including hydrogen. The quantity Xp of the at least one metallic element under the form of carbides, nitrides or carbonitrides is, in weight: 0.030%≦Vp≦0.40% 0.030%≦Tip≦0.50% 0.040%≦Nbp≦0.40% 0.14%≦Mop≦0.44% 0.070%≦Crp≦0.6%. The hydrogen content Hmax designating the maximal hydrogen content that can be measured from a series of at least five specimens, and the quantity Xp, in weight, is such that: 1000  H max X P ≤ 3.3 .

PROCESSES FOR PRODUCING THICKER GAGE PRODUCTS OF NIOBIUM MICROALLOYED STEEL

A process for controlling austenite grain size in austenite processing through nano-scale precipitate engineering of TiN—NbC composites to produce thicker gage product of niobium microalloyed steel includes controlling the base chemical composition of a steel product to include 0.003-0.004 wt. percent nitrogen, 0.012-0.015 wt. percent titanium, 0.03-0.07 wt. percent carbon, and 0.07-0.15 wt. percent nobium; lowering the temperature of roughening to end the roughening operation in the temperature range of from about 980° C. to 1030° C.; retaining greater than about 0.03 wt. percent niobium in solution in the matrix by rapid cooling of the product to enter the finish rolling operation below the temperature of no recrystallization, with an austenite grain size of about 30 microns; and applying reduced rolling reduction in the finish rolling operation. 2. A process as recited in claim 1 , wherein greater than about 0.04 wt % niobium is retained in solution in the matrix.3. A process as recited in claim 1 , wherein austenite grain size is controlled in the range of about 20-40 microns at entry to the finish rolling operation.4. A process as recited in claim 1 , wherein TiN precipitates are in the range of about 10-20 nm and the inter-particle spacing is about 200-300 nm.5. A process as recited in wherein thermodynamic potential for precipitation of NbC occurs towards the end of the roughing operation at temperatures ranging from about 980° C. to about 1030° C.6. A process as recited in claim 1 , wherein TiN—NbC composites are in the size range of about 20-50 nm.7. A process as recited in claim 1 , further comprising applying accelerated cooling upstream between the end of the roughing operation and the start of finish rolling to avoid depletion of solute niobium from the matrix to less than 0.03 wt percent.8. A process as recited in claim 7 , further comprising applying accelerated cooling upstream between the end of the roughing operation and the start of finish rolling ...

THICK, TOUGH, HIGH TENSILE STRENGTH STEEL PLATE AND PRODUCTION METHOD THEREFOR

A thick, high-toughness high-strength steel plate has excellent strength and toughness in the central area through the plate thickness. The thick steel plate has a specific chemical composition and includes a microstructure having, throughout an entire region in the plate thickness direction, an average prior austenite grain size of not more than 50 μm and a martensite and/or bainite phase area fraction of not less than 80%. A continuously cast slab having the specific chemical composition is heated to 1200° C. to 1350° C., hot worked with a strain rate of not more than 3/s and a cumulative working reduction of not less than 15%, and thereafter hot rolled and heat treated. 19-. (canceled)10. A thick , high-toughness high-strength steel plate having a plate thickness of not less than 100 mm , the steel plate comprising a microstructure having , throughout an entire region in a plate thickness direction , an average prior austenite grain size of not more than 50 μm and a martensite and/or bainite phase area fraction of not less than 80%.11. The steel plate according to claim 10 , wherein the yield strength is not less than 620 MPa.12. The steel plate according to claim 10 , wherein a reduction of area after fracture in a tensile test in the direction of the plate thickness of the steel plate is not less than 25%.13. A method of manufacturing a thick claim 10 , high-toughness high-strength steel plate having a plate thickness of not less than 100 mm claim 10 , the steel plate including a microstructure having throughout an entire region in the plate thickness direction claim 10 , an average prior austenite grain size of not more than 50 μm and a martensite and/or bainite phase area fraction of not less than 80% claim 10 , the method comprising:heating a continuously cast slab to 1200° C. to 1350° C.,hot working the slab at not less than 1000° C. with a strain rate of not more than 3/s and a cumulative working reduction of not less than 15%, andhot rolling, quench ...

HIGH-STRENGTH HOT-DIPPED STEEL SHEET HAVING EXCELLENT COATING ADHESION AND METHOD FOR MANUFACTURING SAME

There is provided a high-strength hot-dipped steel sheet having excellent coating adhesion and a method for manufacturing the steel sheet. The steel sheet has a chemical composition, and a coating layer is disposed on the steel sheet. The chemical composition includes, by mass %, C: 0.02% or greater and 0.30% or less, Si: 0.01% or greater and 2.0% or less, Mn: 0.2% or greater and 3.0% or less, P: 0.08% or less, S: 0.02% or less, and Al: 0.001% or greater and 0.40% or less, with the balance being Fe and incidental impurities. The coating layer has a coating weight per side of 30 to 90 g/mand contains exfoliated base steel in an amount of 0.3 to 1.5 g/m. 1. A high-strength hot-dipped steel sheet having a chemical composition comprising , by mass %: C: 0.02% or greater and 0.30% or less , Si: 0.01% or greater and 2.0% or less , Mn: 0.2% or greater and 3.0% or less , P: 0.08% or less , S: 0.02% or less , and Al: 0.001% or greater and 0.40% or less , with a balance being Fe and incidental impurities , the steel sheet comprising a coating layer disposed thereon ,{'sup': 2', '2, 'wherein the coating layer has a coating weight per side in a range of 30 to 90 g/mand contains exfoliated base steel in an amount in a range of 0.3 to 1.5 g/m.'}2. The high-strength hot-dipped steel sheet having excellent coating adhesion according to claim 1 , wherein the chemical composition further comprises claim 1 , by mass % claim 1 , at least one selected from the group consisting of Ti: 0.01% or greater and 0.40% or less claim 1 , Nb: 0.001% or greater and 0.200% or less claim 1 , V: 0.001% or greater and 0.500% or less claim 1 , Mo: 0.01% or greater and 0.50% or less claim 1 , W: 0.001% or greater and 0.200% or less claim 1 , and B: 0.0003% or greater and 0.01% or less.3. A method for manufacturing a high-strength hot-dipped steel sheet having excellent coating adhesion claim 1 , wherein a steel slab having the chemical composition according to is subjected to hot rolling claim 1 , ...

HIGH-STRENGTH PLATED STEEL SHEET AND METHOD FOR PRODUCING SAME

Disclosed herein is a high-strength plated steel sheet containing an internal oxidized layer, a soft layer including the internal oxidized layer, and a hard layer including a structure having metallic structure containing a low-temperature-transformation produced phase in a proportion of 70% or more by area of the whole of the metallic structure, in which polygonal ferrite is in a proportion of 0% or more by area, and 10% or less by area of the same, and retained austenite is in a proportion of 5% or more by volume of the same. The high-strength plated steel sheet satisfies the average depth D of the soft layer is 20 μm or more, the average depth d of the internal oxidized layer is 4 μm or more and less than D, and a tensile strength of 980 MPa or more. 1: A high-strength plated steel sheet having a hot-dip galvanized layer or a hot-dip galvannealed layer on a surface of a base steel sheet , the base steel sheet comprising , in % by mass:C: 0.10 to 0.5%,Si: 1 to 3%,Mn: 1.5 to 8%,Al: 0.005 to 3%,P: more than 0% to 0.1% or less,S: more than 0% to 0.05% or less, andN: more than 0% to 0.01% or less,wherein: an internal oxidized layer comprising at least one an oxide selected from the group consisting of Si and Mn,', 'a soft layer comprising the internal oxidized layer, and having a Vickers hardness of 90% or less of a Vickers hardness of a portion of t/4 of the base steel sheet where “t” is a sheet thickness of the base steel sheet, and', 'a hard layer comprising a structure having metallic structure which comprises, when the metallic structure is observed through a scanning electron microscope, a low-temperature-transformation produced phase in a proportion of 70% or more by area of the whole of the metallic structure, and polygonal ferrite in a proportion of 0 to 10% by area of the whole of the metallic structure;, 'the plated steel sheet sequentially comprises, from an interface between the base steel sheet and the galvanized layer or galvannealed layer toward the ...

HOT-ROLLED STEEL SHEET HAVING EXCELLENT DURABILITY AND METHOD FOR MANUFACTURING SAME

The present invention relates to steel used for a sash component and the like of a vehicle and, more specifically, to a hot-rolled steel sheet having excellent durability and a method for manufacturing same, the hot-rolled steel sheet having no cracks formed on a material and a welding heat-affected zone (HAZ) even after pipemaking and molding due to a smaller decrease in the strength of the welding heat-affected zone formed during electric resistance welding in comparison with the strength of the material (base material). 1. A hot-rolled steel sheet having excellent durability , comprising:by weight %, 0.05-0.14% of carbon (C), 0.1-1.0% of silicon (Si), 0.8-1.8% of manganese (Mn), 0.001-0.03% of phosphorous (P), 0.001-0.01% of sulfur (S), 0.1-0.5% of soluble aluminum (Sol.Al), 0.3-1.0% of chromium (Cr), 0.01-0.05% of titanium (Ti), 0.03-0.06% of niobium (Nb), 0.04-0.1% of vanadium (V), 0.001-0.01% of nitrogen (N), and a balance of Fe and inevitable impurities,wherein Mn and Si satisfy relational formula 1 as below,wherein a microstructure includes a hard phase including martensite and bainite phases mixed therein with a ferrite phase as a matrix structure, and {'br': None, '4 Подробнее

STEEL MATERIAL SUITABLE FOR USE IN SOUR ENVIRONMENT

The steel material according to the present disclosure contains a chemical composition consisting of, in mass %, C: 0.20 to 0.50%, Si: 0.05 to 1.00%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.20 to 1.50%, Mo: 0.25 to 1.50%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.0100% or less and O: 0.0100% or less, with the balance being Fe and impurities. The steel material contains an amount of dissolved C within a range of 0.010 to 0.050 mass %. The steel material also has a yield strength within a range of 965 to 1069 MPa, and a yield ratio of the steel material is 90% or more. 1. A steel material comprising:a chemical composition consisting of, in mass %,C: 0.20 to 0.50%,Si: 0.05 to 1.00%,Mn: 0.05 to 1.00%,P: 0.025% or less,S: 0.0100% or less,Al: 0.005 to 0.100%,Cr: 0.20 to 1.50%,Mo: 0.25 to 1.50%,Ti: 0.002 to 0.050%,B: 0.0001 to 0.0050%,N: 0.0100% or less,O: 0.0100% or less,V: 0 to 0.60%,Nb: 0 to 0.030%,Ca: 0 to 0.0100%,Mg: 0 to 0.0100%,Zr: 0 to 0.0100%,Co: 0 to 0.50%,W: 0 to 0.50%,Ni: 0 to 0.50%,Cu: 0 to 0.50%,rare earth metal: 0 to 0.0100%, andwith the balance being Fe and impurities,an amount of dissolved C within a range of 0.010 to 0.050 mass %,a yield strength within a range of 965 to 1069 MPa, anda yield ratio of 90% or more.2. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from the group consisting of:V: 0.01 to 0.60%, andNb: 0.002 to 0.030%.3. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from the group consisting of:Ca: 0.0001 to 0.0100%,Mg: 0.0001 to 0.0100%, andZr: 0.0001 to 0.0100%.4. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from the group consisting of:Co: 0.02 to 0.50%, andW: 0.02 to 0.50%.5. The steel material according to any one of claim 1 , wherein the chemical composition ...

HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING SAME

A high-strength steel sheet includes a steel structure with: ferrite being 35% to 80% and tempered martensite being greater than 5% and 20% or less in terms of area fraction; retained austenite being 8% or more in terms of volume fraction; an average grain size of: the ferrite being 6 μm or less; and the retained austenite being 3 μm or less; a value obtained by dividing an area fraction of blocky austenite by a sum of area fractions of lath-like austenite and the blocky austenite being 0.6 or more; a value obtained by dividing, by mass %, an average Mn content in the retained austenite by an average Mn content in the ferrite being 1.5 or more; and a value obtained by dividing, by mass %, an average C content in the retained austenite by an average C content in the ferrite being 3.0 or more. 18.-. (canceled)9. A high-strength steel sheet comprising:a component composition including: by mass %, C: 0.030% to 0.250%; Si: 0.01% to 3.00%; Mn: 3.10% to 4.20%; P: 0.001% to 0.100%; S: 0.0001% to 0.0200%; N: 0.0005% to 0.0100%; Al: 0.010% to 1.200%; and balance Fe and inevitable impurities; and ferrite being 35% to 80% and tempered martensite being greater than 5% and 20% or less in terms of area fraction;', 'retained austenite being 8% or more in terms of volume fraction;', 'an average grain size of the ferrite being 6 μm or less;', 'an average grain size of the retained austenite being 3 μm or less;', 'a value obtained by dividing an area fraction of blocky austenite by a sum of area fractions of lath-like austenite and the blocky austenite being 0.6 or more;', 'a value obtained by dividing an average Mn content, by mass %, in the retained austenite by an average Mn content, by mass %, in the ferrite being 1.5 or more; and', 'a value obtained by dividing an average C content, by mass %, in the retained austenite by an average C content, by mass %, in the ferrite being 3.0 or more., 'a steel structure with10. The high-strength steel sheet according to claim 9 , wherein the ...

LOW-TEMPERATURE STEEL MATERIAL HAVING EXCELLENT TOUGHNESS IN WELDING PORTION THEREOF AND MANUFACTURING METHOD THEREFOR

Provided according to a preferable aspect of the present invention are a low-temperature steel material having excellent toughness in a welding portion thereof and a manufacturing method therefor, the low-temperature steel material comprising, by weight %, 0.02-0.06% of C, 6.0-7.5% of Ni, 0.4-1.0% of Mn, 0.02-0.15% of Si, 0.02-0.3% of Mo, 0.02-0.3% of Cr, 50 ppm or less of P, 10 ppm or less of S, 0.005-0.015% of Ti, 60 ppm or less of N, with a Ti/N weight % ratio of 2.5 of 4, and the balance of iron (Fe) and other inevitable impurities; and having: an effective grain size of 50 micrometers or less, with a boundary angle found to be 15 degrees or greater as measured by EBSD in an area of a fusion line (FL)-FL+1 mm in a weld heat-affected zone of a weld portion welded at a heat input of 5-50 kJ/cm; and an impact toughness of 70 J or higher at −196° C. as measured in an area of fusion line (FL)-FL+1 mm. 1. A low-temperature steel material having excellent welding-portion toughness , comprising:in weight %, 0.02 to 0.06% of C, 6.0 to 7.5% of Ni, 0.4 to 1.0% of Mn, 0.02 to 0.15% of Si, 0.02 to 0.3% of Mo, 0.02 to 0.3% of Cr, 50 ppm or less of P, 10 ppm or less of S, 0.005 to 0.015% of Ti, 60 ppm or less of N, a Ti/N weight % ratio of 2.5 of 4, and a balance of iron (Fe) and other unavoidable impurities,wherein in a weld heat-affected zone of a welding portion welded with a heat input of 5 to 50 kJ/cm, an effective grain size having a boundary angle of 15 degrees or greater in an area of a fusion line (FL) to FL+1 mm, measured by EBSD, is 50 micrometers or less, and an impact toughness measured in the area of the fusion line (FL) to FL+1 mm is 70 J or higher at −196° C.2. The low-temperature steel material having excellent welding-portion toughness of claim 1 , wherein a yield strength of the low-temperature steel material is 585 MPa or higher.3. The low-temperature steel material having excellent welding-portion toughness of claim 1 , wherein an impact transition ...

HIGH-STRENGTH GALVANIZED STEEL SHEET, HIGH STRENGTH MEMBER, AND METHOD FOR MANUFACTURING THE SAME

A high-strength galvanized steel sheet of the present invention includes a steel sheet having a specific chemical composition, and a steel structure containing, in terms of area ratio, 4% or more and 20% or less of retained austenite, 30% or less (including 0%) of ferrite, 40% or more of martensite, and 10% or more and 50% or less of bainite; and a galvanized layer provided on the steel sheet, in which an amount of diffusible hydrogen in the steel is less than 0.20 mass ppm, a tensile strength is 1100 MPa or more, a relationship between a tensile strength TS (MPa), an elongation El (%), and a sheet thickness t (mm) satisfies a (1) formula below, and a yield ratio YR is 67% or more. 1. A high-strength galvanized steel sheet comprising:a steel sheet having a chemical composition containing, in mass %,C: 0.10% or more and 0.30% or less,Si: 1.0% or more and 2.8% or less,Mn: 2.0% or more and 3.5% or less,P: 0.010% or less,S: 0.001% or less,Al: 1% or less,N: 0.0001% or more and 0.006% or less, and the balance: Fe and incidental impurities, anda steel structure containing, in terms of area ratio, 4% or more and 20% or less of retained austenite, 30% or less (including 0%) of ferrite, 40% or more of martensite, and 10% or more and 50% or less of bainite; anda galvanized layer provided on the steel sheet,wherein an amount of diffusible hydrogen in the steel is less than 0.20 mass ppm,a tensile strength is 1100 MPa or more,a relationship between a tensile strength TS (MPa), an elongation El (%), and a sheet thickness t (mm) satisfies a (1) formula below, and {'br': None, 'i': 't', 'TS×(El+3−2.5)≤13000 \u2003\u2003(1).'}, 'a yield ratio YR is 67% or more,'}2. The high-strength galvanized steel sheet according to claim 1 ,wherein the chemical composition further contains at least one of, in mass %,one or more of Ti, Nb, V, and Zr: 0.005% or more and 0.10% or less in total,one or more of Mo, Cr, Cu, and Ni: 0.005% or more and 0.5% or less in total, andB: 0.0003% or more and 0. ...

HIGH HARDNESS WEAR-RESISTANT STEEL WITH EXCELLENT TOUGHNESS AND CUTTING CRACK RESISTANCE AND METHOD FOR MANUFACTURING SAME

The present invention relates to a high hardness wear-resistant steel with excellent toughness and cutting crack resistance, and a method for manufacturing the same. A high hardness wear-resistant steel according to one aspect of the present invention has a composition containing, by weight ratio, 2.1 to 4.0% of manganese (Mn), 0.15 to 0.2% of carbon (C), 0.02 to 0.5% of silicon (Si), 0.2 to 0.7% of chromium (Cr), a remainder of iron (Fe) and other unavoidable impurities, has a microstructure in which prior austenite grain size is 25 μm or less and martensite is included as a main phase, and has excellent toughness and cutting crack resistance which satisfies a condition in which Ac3-Ac1 is 100° C. or lower. 1. A high hardness wear-resistant steel:having a composition containing, by weight ratio, 2.1 to 4.0% of manganese (Mn), 0.15 to 0.2% of carbon (C), 0.02 to 0.5% of silicon (Si), 0.2 to 0.7% of chromium (Cr), a remainder of iron (Fe) and other unavoidable impurities;having a microstructure in which prior austenite grain size is 25 μm or less and martensite is included as a main phase; andhaving excellent toughness and cutting crack resistance which satisfies a condition in which Ac3-Ac1 is 100° C. or lower.2. The high hardness wear-resistant steel according to claim 1 , further comprising claim 1 , by weight ratio claim 1 , 0.1% or less of niobium (Nb) claim 1 , 0.02% or less of boron (B) claim 1 , and 0.1% or less of titanium (Ti).3. The high hardness wear-resistant steel according to claim 1 , wherein the structure of martensite comprises 95% or more in area fraction.4. The high hardness wear-resistant steel according to claim 1 , wherein Brinell hardness is 420 to 480 claim 1 , and Charpy impact energy is 35 J or more at −40° C.5. The high hardness wear-resistant steel according to claim 1 , wherein the martensite does not contain carbides therein.6. A method of manufacturing a high hardness wear-resistant steel having excellent toughness and cutting crack ...

Lean duplex stainless steel having improved corrosion resistance and machinability, and manufacturing method therefor

A lean duplex stainless steel and a method of manufacturing the same are provided. The lean duplex stainless steel includes, in percent (%) by weight of the entire composition, 0.08% or less of carbon (C) (excluding 0), 0.7 to 1.1% of silicon (Si), 2.4 to 3.5% of manganese (Mn), 17.9 to 20.7% of chromium (Cr), 0.05 to 1.15% of nickel (Ni), 0.18 to 0.3% of nitrogen (N), 0.4 to 2.8% of copper (Cu), and the remainder of iron (Fe) and inevitable impurities, wherein a predicted pitting potential is from 360 to 440 mV. Thus, manufacturing costs may be reduced via adjustment of components of the duplex stainless steel and both of formability and corrosion resistance may be improved by improving corrosion resistance and increasing elongation. Formability may be improved by inhibiting formation of thermal martensite and increasing elongation via adjustment of cooling conditions during coiling and cooling after hot rolling.

Method For Producing an Ultra High Strength Galvannealed Steel Sheet and Obtained Galvannealed Steel Sheet

A method for producing a coated steel sheet having a tensile strength of at least 1450 MPa and a total elongation of at least 17% is provided. The method includes providing a cold rolled steel sheet having a chemical composition in weight %: 0.34%≤C≤0.45%, 1.50%≤Mn≤2.30%, 1.50%≤Si≤2.40%, 0% Подробнее

Austenitic stainless steel having improved processability

Disclosed is an austenitic stainless steel with increased workability. The austenitic stainless steel includes, based on % by weight, silicon (Si): 0.1 to 0.65%, manganese (Mn): 0.2 to 3.0%, nickel (Ni): 6.5 to 10.0%, chromium (Cr): 16.5 to 20.0%, copper (Cu): 6.0% or less (excluding 0), the sum of carbon (C) and nitrogen (N): 0.08% or less (excluding 0), and the remainder being Fe and unavoidable impurities, wherein the austenitic stainless steel has a work hardening rate of 1500 MPa or less within a true strain range of 0.15 to 0.4. Therefore, when a sink bowl and the like are processed using the austenitic stainless steel, the true strain and work hardening rate of which are controlled, the occurrence of delayed fracture in a molded corner thereof, which has been subjected to a large amount of processing, can be prevented.

STEEL SHEET, METHOD OF MANUFACTURING SAME, CROWN CAP, AND DRAWING AND REDRAWING (DRD) CAN

Provided is a steel sheet having sufficient formability and strength even after sheet metal thinning, the steel sheet including: a chemical composition containing, by mass %, C: more than 0.0060% and not more than 0.012%, Si: 0.02% or less, Mn: 0.10% or more and 0.60% or less, P: 0.020% or less, S: 0.020% or less, Al: 0.01% or more and 0.07% or less, and N: 0.0080% or more and 0.0200% or less, with the balance being Fe and inevitable impurities, in which a dislocation density at a depth position of ½ of a sheet thickness from a surface of the steel sheet is 2.0×10/mor more and 1.0×10/mor less. 1. A steel sheet comprising: C: more than 0.006% and not more than 0.012%,', 'Si: 0.02% or less,', 'Mn: 0.10% or more and 0.60% or less,', 'P: 0.020% or less,', 'S: 0.020% or less,', 'Al: 0.01% or more and 0.07% or less, and', 'N: 0.0080% or more and 0.0200% or less,, 'a chemical composition containing, by mass %,'}with the balance being Fe and inevitable impurities; wherein{'sup': 14', '2', '15', '2, 'a dislocation density at a depth position of ½ of a sheet thickness from a surface of the steel sheet is 2.0×10/mor more and 1.0×10/mor less.'}2. The steel sheet according to claim 1 , having a thickness of 0.20 mm or less.3. A crown cap made of the steel sheet as recited in .4. A DRD can made of the steel sheet as recited in .5. A method of manufacturing the steel sheet as recited in claim 1 , comprising:a hot rolling step of heating a steel raw material at 1200° C. or higher, finish rolling the steel raw material to obtain a hot rolled sheet, and then coiling the hot rolled sheet within a temperature range of 670° C. or lower;a pickling step of pickling the hot rolled sheet after the hot rolling step;a primary cold rolling step of cold rolling the hot rolled sheet after the pickling step to obtain a cold rolled sheet;an annealing step of annealing the cold rolled sheet after the primary cold rolling step in a temperature range of 650° C. to 750° C. to obtain an annealed sheet; ...

HOT ROLLED STEEL PRODUCT WITH ULTRA-HIGH STRENGTH MINIMUM 1100MPA AND GOOD ELONGATION 21%

Present invention discloses a high strength hot rolled steel product with tensile strength at least 1100 MPa and elongation not less than 21%. The steel further has uniform elongation not less than 10% and yield and tensile ratio 0.6-0.7. The steel further has tensile toughness in the range 19-23.5 GPa %. The developed steel is primarily aimed for automotive structural applications and also for many other such as defence where good combination of strength and ductility required is very high. The developed steel product has following composition C: 0.15-0.23, Mn: 0.8-2.1, Si: 0.3-1.1, Cr: 0.8-1.3, Mo: 0.08-0.25, Nb: 0.018-0.035, Ti—0.01-0.1 S—0.008 max, P—0.025 max, Al—0.05 to 0.3, N—0.005 max. The liquid metal was continuous cast into slab casting. The cast slab was soaked above 1150° C. for few hours and subsequently the cast structure was broken by deformation prior to hot rolling. The slab was then hot rolled into strip with thickness not less than 10 mm with finish rolling temperature in austenite region and subsequently cooled to above Ms (martensite temperature) but below Bs (Below Bainite start temperature) to avoid polygonal ferrite. The steel with above mentioned properties was developed using existing hot rolling. 1. An ultra-high-strength hot-rolled steel strip or sheet with tensile strength of at least 1100 MPa and total elongation not less than 21% , comprising in weight percentage:C: 0.12 to 0.24;Mn: 0.8 to 2.1;Si: 0.4 to 1.1;Cr: 0.8 to 1.5;Al—0.05 to 0.3;Mo: 0.05 to 0.25;Nb: 0.018 to 0.035;Ti—0.01 to 0.1;S—0.008 max’P—0.025 max; andN—0.005 max.2. The ultra-high-strength hot-rolled steel strip or sheet as claimed in claim 1 , wherein Mo claim 1 , Si claim 1 , Al claim 1 , Ti claim 1 , Cr varies preferably in the range of 0.08 to 0.12 claim 1 , 0.4 to 0.8 claim 1 , 0.1 to 0.29 claim 1 , 0.02 to 0.04 and 0.85 to 1.1 respectively.3. The ultra-high-strength hot-rolled steel strip or sheet as claimed in claim 1 , wherein the steel has YS to TS greater than ...

STAINLESS STEEL FOR POLYMER FUEL CELL SEPARATION PLATE HAVING IMPROVED HYDROPHILICITY AND CONTACT RESISTANCE AND METHOD FOR MANUFACTURING SAME

Stainless steel with improved hydrophilicity and contact resistance for a Polymer Electrolyte Membrane Fuel Cell (PEMFC) separator, and a method of manufacturing the stainless steel Stainless steel are disclosed. Stainless steel for a Polymer Electrolyte Membrane Fuel Cell (PEMFC) separator according to an embodiment of the present disclosure may include: by weight percent, 0 to 0.02% of C (excluding 0), 0 to 0.02% of N (excluding 0), 0 to 0.25% of Si (excluding 0), 0 to 0.2% of Mn (excluding 0), 0 to 0.04% of P (excluding 0), 0 to 0.02% of S (excluding 0), 20 to 34% of Cr, 0 to 0.6% of V (excluding 0), 0 to 0.5% of Ti (excluding 0), 0 to 0.5% of Nb (excluding 0), and the remainder comprising iron (Fe) and other unavoidable impurities, wherein a plurality of patterns may be formed on a surface of the stainless steel in a direction that is inclined with respect to a rolling direction, and the plurality of patterns are arranged repeatedly in the rolling direction. 1. Stainless steel with improved hydrophilicity and contact resistance for a Polymer Electrolyte Membrane Fuel Cell (PEMFC) separator , the stainless steel comprising:by weight percent, 0 to 0.02% of C (excluding 0), 0 to 0.02% of N (excluding 0), 0 to 0.25% of Si (excluding 0), 0 to 0.2% of Mn (excluding 0), 0 to 0.04% of P (excluding 0), 0 to 0.02% of S (excluding 0), 20 to 34% of Cr, 0 to 0.6% of V (excluding 0), 0 to 0.5% of Ti (excluding 0), 0 to 0.5% of Nb (excluding 0), and the remainder comprising iron (Fe) and other unavoidable impurities,wherein a plurality of patterns are formed on a surface of the stainless steel in a direction that is inclined with respect to a rolling direction, and the plurality of patterns are arranged repeatedly in the rolling direction.2. The stainless steel of claim 1 , wherein the patterns are formed in a direction that is inclined at 35 to 60 degrees with respect to the rolling direction.3. The stainless steel of claim 1 , wherein the patterns are parallel to each other ...

HIGH-STRENGTH COLD ROLLED STEEL SHEET HAVING HIGH HOLE EXPANSION RATIO, HIGHSTRENGTH HOT-DIP GALVANIZED STEEL SHEET, AND MANUFACTURING METHODS THEREFOR

Provided is a high-strength cold rolled steel sheet, a high-strength hot-dip galvanized steel sheet manufactured using the cold rolled steel sheet, and manufacturing methods therefor, the high-strength cold rolled steel sheet comprising, by wt %, 0.17-0.21% of carbon (C), 0.3-0.8% of silicon (Si), 2.7-3.3% of manganese (Mn), 0.3-0.7% of chromium (Cr), 0.01-0.3% of aluminum (Al), 0.01-0.03% of titanium (Ti), 0.001-0.003% of boron (B), 0.04% or less of phosphorus (P), 0.02% or less of sulfur (S), 0.01% or less of nitrogen (N) and the balance of iron (Fe) and other inevitable impurities, wherein the amounts of carbon (C), silicon (Si) and aluminum (Al) satisfy the following mathematical relation (1). [Mathematical relation (1)] [C]+([Si]+[Al])/5≤0.35% (wherein [C], [Si] and [Al] respectively mean the wt % of C, Si and Al.) 1. A high-strength cold rolled steel sheet comprising: {'br': None, '[C]+([Si]+[Al])/5≤0.35%\u2003\u2003[Equation (1)]'}, 'by weight percent (wt %), 0.17 to 0.21% of carbon (C), 0.3 to 0.8% of silicon (Si), 2.7 to 3.3% of manganese (Mn), 0.3 to 0.7% of chromium (Cr, 0.01 to 0.3% of aluminum (Al), 0.01 to 0.03% of titanium (Ti), 0.001 to 0.003% of boron (B), 0.04% or less of phosphorus (P), 0.02% or less of sulfur (S), 0.01% or less of nitrogen (N), the balance of iron (Fe), and other inevitable impurities, wherein the contents of carbon (C), silicon (Si), and aluminum (Al) satisfy Equation 1 below, a microstructure thereof includes, by area fraction, 3 to 7% of retained austenite, 5 to 15% of fresh martensite, 5% or less (including 0%) of ferrite, and the balance of bainite or tempered martensite, and, by volume fraction, 1 to 3% of a cementite phase, as a second phase, is precipitated and distributed between bainite laths or in the laths or grain boundary of a tempered martensite phase,'}wherein [C], [Si], [Al] refer to weight percents of C, Si, and Al, respectively.2. The high-strength cold rolled steel sheet of claim 1 , wherein the cold rolled ...

NON-GRAIN ORIENTED ELECTRICAL STEEL AND METHOD FOR MANUFACTURING SAME

A non-oriented electrical steel sheet according to an embodiment of the present invention includes: in wt %, C at 0.004 wt % or less (excluding 0 wt %), Si at 2.5 to 4.0 wt %, P at 0.1 wt % or less (excluding 0 wt %), Al at 0.3 to 2.0 wt %, N at 0.003 wt % or less (excluding 0 wt %), S at 0.003 wt % or less (excluding 0 wt %), Mn at 0.15 to 2.5 wt %, Cr at 0.5 wt % (excluding 0 wt %), and the balance including Fe and other impurities unavoidably added thereto; satisfies the following Equation 1; and has an average grain size of 20 μm or less. 1. A non-oriented electrical steel sheet , comprising:in wt %, C at 0.004 wt % or less (excluding 0 wt %), Si at 2.5 to 4.0 wt %, P at 0.1 wt % or less (excluding 0 wt %), Al at 0.3 to 2.0 wt %, N at 0.003 wt % or less (excluding 0 wt %), S at 0.003 wt % or less (excluding 0 wt %), Mn at 0.15 to 2.5 wt %, Cr at 0.5 wt % (excluding 0 wt %), and the balance including Fe and other impurities unavoidably added thereto;satisfying Equation 1 below; and {'br': None, '[Mn]≥1450×[S]−0.8\u2003\u2003[Equation 1]'}, 'having an average grain size of 20 μm or less(in Equation 1, [Mn] and [S] represent a content (wt %) of Mn and S, respectively.)2. The non-oriented electrical steel sheet of claim 1 , further comprisingone or more of Ti at 0.003 wt % or less, Nb at 0.003 wt % or less, and Cu at 0.1 wt % or less.3. The non-oriented electrical steel sheet of claim 1 , wherein{'sup': '2', 'a density of sulfide having a diameter of 1 nm to 0.1 μm is 250,000/mmor less.'}4. The non-oriented electrical steel sheet of claim 3 , whereinthe sulfide includes MnS, MnS, or CuS.5. The non-oriented electrical steel sheet of claim 1 , wherein{'sub': '50', 'a magnetic flux density (B) induced in a magnetic field of 5000 is 1.61 T or more, and the non-oriented electrical steel sheet has a yield strength of 500 MPa or more.'}6. The non-oriented electrical steel sheet of claim 1 , wherein{'sub': '10/400', 'iron loss (W) measured after stress relief annealing that ...

HIGH-STRENGTH STAINLESS STEEL

A stainless steel with a yield strength of 2,200 MPa or more is disclosed through the generation of the strain-induced martensite phase and the increase of the martensite phase strength. A high strength stainless steel according to an embodiment of present disclosure includes, in percent (%) by weight of the entire composition, C: 0.14 to 0.20%, Si: 0.8 to 1.0%, Mn: more than 0 and 0.5% or less, Cr: 15.0 to 17.0%, Ni: 4.0 to 5.0%, Mo: 0.6 to 0.8%, Cu: 0.5% or less, N: 0.05 to 0.11%, the remainder of iron (Fe) and other inevitable impurities, and C+N: 0.25% or more and Md30 value satisfies 40° C. or more. 1. A high strength stainless steel comprising , in percent (%) by weight of the entire composition , C: 0.14 to 0.20% , Si: 0.8 to 1.0% , Mn: more than 0 and 0.5% or less , Cr: 15.0 to 17.0% , Ni: 4.0 to 5.0% , Mo: 0.6 to 0.8% , Cu: 0.5% or less , N: 0.05 to 0.11% , the remainder of iron (Fe) and other inevitable impurities , and {'br': None, 'Md30(° C.)=551−462*(C+N)−9.2*Si−8.1*Mn−13.7*Cr−29*(Ni+Cu)−18.5*Mo\u2003\u2003(1)'}, 'C+N: 0.25% or more and Md30 value represented by a following Equation (1) satisfies 40° C. or more.'}(Here, C, N, Si, Mn, Cr, Ni, Cu, Mo mean the content (% by weight) of each element)2. The high strength stainless steel of claim 1 , wherein a Ms value represented by a following Equation (2) satisfies −110° C. or less.{'br': None, 'Ms(° C.)=502−810*C−1230*N−13*Mn−30*Ni−12*Cr−54*Cu−46*Mo\u2003\u2003(2)'}3. The high strength stainless steel of claim 2 , wherein the Ms value represented by the Equation (2) satisfies −117° C. or less claim 2 , or a value of a following Equation (3) satisfies 17.0 or more.{'br': None, 'Ni/(C+N)\u2003\u2003(3)'}4. The high strength stainless steel of claim 1 , wherein a matrix structure comprises claim 1 , as an area fraction claim 1 , a martensite phase of 45% or more claim 1 , a residual austenite phase and ferrite phase claim 1 , andthe ferrite phase is 4% or less.5. The high strength stainless steel of claim 1 , ...

CR-BASED STAINLESS STEEL HAVING EXCELLENT HYDROGEN EMBRITTLEMENT RESISTANCE

A Cr-based stainless steel sheet includes: 0.020 mass % or less of C; 1.00 mass % or less of Si; 1.00 mass % or less of Mn; 0.040 mass % or less of P; 0.0030 mass % or less of S; 10.0 to 18.0 mass % of Cr; 0.020 mass % or less of N; 0.10 mass % or less of Al; and one or both of 0.5 mass % or less of Nb and 0.5 mass % or less of Ti; in which a texture in a sheet surface satisfies (i) and (ii) below. (i) In the sheet surface, an area ratio of crystal grains ({211}±10-degree-oriented grains) whose orientation difference between a normal direction of the surface and a {211}-plane orientation is 10 degrees or less is less than 30%. (ii) For the {211}±10-degree-oriented grains, a length in a rolling direction and a length in a sheet width direction are each less than 0.15 mm on average. 1. A Cr-based stainless steel sheet comprising:0.020 mass % or less of C;1.00 mass % or less of Si;1.00 mass % or less of Mn;0.040 mass % or less of P;0.0030 mass % or less of S;10.0 to 18.0 mass % of Cr;0.020 mass % or less of N;0.10 mass % or less of Al;one or both of 0.5 mass % or less of Nb and 0.5 mass % or less of Ti;0 to 0.3 mass % of Sn;0 to 0.005 mass % of B;0 to 1 mass % of Ni;0 to 1 mass % of Cu;0 to 1 mass % of Mo;0.2 mass % or less of Sb;0 to 0.5 mass % of V;0 to 0.5 mass % of W;0 to 0.5 mass % of Zr;0 to 0.5 mass % of Co;0 to 0.005 mass % of Mg;0 to 0.005 mass % of Ca;0 to 0.020 mass % of Ga;0 to 0.1 mass % of La;0 to 0.1 mass % of Y;0 to 0.1 mass % of Hf;0 to 0.1 mass % of REM; and 'wherein a texture in a sheet surface of the Cr-based stainless steel sheet satisfies (i) and', 'a balance consisting of Fe and impurities,'}(ii) below,(i) in the sheet surface, an area ratio of crystal grains (hereinafter referred to as “{211}±10-degree-oriented grains”) whose orientation difference between a normal direction of a surface of the steel sheet and a {211}-plane orientation is 10 degrees or less is less than 30%, and(ii) for the {211}±10-degree-oriented grains defined in (i), a ...

METHOD OF PRODUCING PRESS-HARDENED AND COATED STEEL PARTS AT A HIGH PRODUCTIVITY RATE

This invention relates to a sheet or pre-coated blank comprising a steel substrate for heat treatment, overlaid on at least a part of at least one of its principal faces, by a pre-coating having, at least one layer of aluminum or aluminum alloy overlaid, on at least a part of the above-mentioned pre-coating, by a polymerized layer having a thickness between 2 and 30 μm composed of a polymer that does not contain silicon, and the nitrogen content of which, is greater than 1% by weight expressed in relation to the above-mentioned layer, wherein the above-mentioned polymerized layer contains carbon pigments in a quantity between 3 and 30% by weight, expressed in relation to said layer. 112310. Sheet or pre-coated blank comprising a steel substrate for heat treatment () overlaid on at least a part of at least one of its main faces by a pre-coating () comprising at least one layer of aluminum or aluminum alloy overlaid on at least a part of the above-mentioned pre-coating by a polymerized layer () having a thickness between 2 μm and 30 μm composed of a polymer that does not contain silicon , and the nitrogen content of which is greater than 1% by weight expressed in relation to the above-mentioned layer , wherein the above-mentioned polymerized layer contains carbon pigments in a quantity between 3 and 30% by weight , expressed in relation to above-mentioned layer.2. Sheet or blank according to claim 1 , characterized in that the elements of said polymer are selected from a list consisting of C claim 1 , H claim 1 , O claim 1 , N.3. Sheet or blank according to claim 1 , characterized in that the polymerized layer is obtained from a resin in the form of a dispersion or emulsion in aqueous phase.4. Sheet or blank according to claim 1 , characterized in that the polymerized layer is obtained from a resin in the form of solution in a non-aqueous solvent.5. Sheet or blank according to claim 1 , characterized in that the polymerized layer is constituted by a film roll-bonded ...

HIGH FORMABILITY DUAL PHASE STEEL

To improve the formability of dual phase steels, the martensite phase is tempered. It may form a ferrite-carbide structure. The tempering step occurs after martensite has been formed in the dual phase steel. The tempering step can occur in a box annealing step or it can be performed in a continuous fashion, such as on a continuous annealing, continuous tempering heat treating, or continuous coating line. The tempering step can further comprise a temper rolling on a temper mill after the heating step. 1. A method of improving the formability of a dual phase steel strip comprising ferrite and martensite , the method comprising the step of temper heat treating the dual phase steel strip at a temperature and for a time sufficient to transform at least a portion of the martensite to ferrite and cementite.2. The method of further comprising the step of temper rolling the dual phase steel after the temper heat treating step.3. The method of wherein the temper heat treating step occurs after the strip has been cold rolled.4. The method of wherein the temper heat treating step occurs after the strip has been coated with a coating.5. The method of wherein the temper heat treating step is a box annealing step.6. The method of wherein the temper heat treating step is a continuous temper heating step.7. The method of wherein the continuous temper heating is provided by induction heating.8. A method of improving the formability of a dual phase steel having a nominal tensile strength of 780 MPa comprising the step of temper heat treating the dual phase steel strip at a temperature for a time such that yield x<110 micrometers.9. The method of wherein the yield x<90 micrometers.10. A method of improving the formability of a dual phase steel having a nominal tensile strength of 980 MPa comprising the step of temper heat treating the dual phase steel strip at a temperature for a time such that yield x<100 micrometers.11. The method of claim 10 , wherein the yield x<10 micrometers.12. ...

PROCESS FOR MANUFACTURING PRESS-HARDENED COATED STEEL PARTS AND PRECOATED SHEETS ALLOWING THESE PARTS TO BE MANUFACTURED

This invention relates to a cold-rolled sheet that is annealed and pre-coated for the fabrication of press hardened parts, composed of a steel substrate for heat treatment with a carbon content Cbetween 0.07% and 0.5%, whereby this content is expressed by weight, and a metal pre-coating on at least the two principal faces of the steel substrate, characterized in that the substrate comprises a decarburized area on the surface of each of the two principal faces, whereby the depth pof the decarburized area is between 6 and 30 micrometers, whereby pis the depth at which the carbon content is equal to 50% of the content C, and in that the sheet does not contain a layer of iron oxide between the substrate and the metal pre-coating.

Thick steel sheet having excellent ctod properties in multilayer welded joints, and manufacturing method for thick steel sheet

There is provided a thick steel plate having good multipass weld joint CTOD characteristics for low to medium heat input and a method for manufacturing the thick steel plate. A steel plate containing, on a mass percent basis, C: 0.03% to 0.12%, Si: 0.5% or less, Mn: 1.0% to 2.0%, P: 0.015% or less, S: 0.0005% to 0.0050%, Al: 0.005% to 0.060%, Ni: 0.5% to 2.0%, Ti: 0.005% to 0.030%, N: 0.0015% to 0.0065%, O: 0.0010% to 0.0050%, Ca: 0.0005% to 0.0060%, and optionally one or two or more of Cu and the like, wherein Ti/N, Ceq, Pcm, and ACR are in particular ranges, a base material of the plate has an effective grain size of 20 μm or less at half the thickness of the plate, and the plate contains a particular number of complex inclusions at ¼ and ½ of the thickness of the plate, the complex inclusions being composed of a sulfide containing Ca and Mn and an oxide containing Al and having an equivalent circular diameter of 0.1 μm or more. Steel having the composition described above is heated at a particular temperature, is then hot-rolled, and is cooled.

FERRITIC STAINLESS STEEL FOR EXHAUST SYSTEM MEMBER HAVING EXCELLENT CORROSION RESISTANCE AFTER HEATING

A ferritic stainless steel for exhaust system components excellent in corrosion resistance after heating includes: 0.015 mass % or less of C; 0.02 mass % or less of N; 0.03 mass % to 1.0 mass of Si; 1.0 mass of Mn; 0.04 mass of P; 0.01 mass of S; 10.5 mass % to 22.5 mass of Cr; 0.02 mass % to 0.5 mass of Sn; 0.003 mass % to 0.2 mass of Al; one or both of 0.03 mass % to 0.35 mass of Ti and 0.03 mass % to 0.6 mass of Nb; and a remnant comprising Fe and inevitable impurities, wherein a grain size number on a surface of the ferritic stainless steel is 6 to 2 to 15 nm of a layer containing Sn at a concentration twice or more of Sn content in the base material is formed on the ferritic stainless steel. 113-. (canceled)14. A ferritic stainless steel for exhaust system components excellent in corrosion resistance after heating , the ferritic stainless steel comprising:0.015 mass % or less of C;0.02 mass % or less of N;0.03 mass % to 1.0 mass % of Si;1.0 mass % or less of Mn;0.04 mass % or less of P;0.01 mass % or less of S;10.5 mass % to 22.5 mass % of Cr;0.02 mass % to 0.5 mass % of Sn;0.003 mass % to 0.2 mass % of Al;one or both of 0.03 mass % to 0.35 mass % of Ti and 0.03 mass % to 0.6 mass % of Nb; anda remnant comprising Fe and inevitable impurities, whereina grain size number on a surface of the ferritic stainless steel is 6 or more, and2 to 15 nm of a layer containing Sn at a concentration twice or more of a Sn concentration in a base material is formed on the ferritic stainless steel when the ferritic stainless steel is heated at 673 K for 24 hours in the atmosphere.15. A ferritic stainless steel for exhaust system components excellent in corrosion resistance after heating , the ferritic stainless steel comprising:0.015 mass % or less of C;0.02 mass % or less of N;0.03 mass % to 1.0 mass % of Si;1.0 mass % or less of Mn;0.04 mass % or less of P;0.01 mass % or less of S;10.5 mass % to 22.5 mass % of Cr;0.02 mass % to 0.5 mass % of Sn;0. 003 mass % to 0.2 mass % of Al ...

HIGH-STRENGTH STEEL SHEET AND PRODUCTION METHOD THEREFOR

A steel sheet has a microstructure that contains ferrite in an area ratio of 20% or more, martensite in an area ratio of 5% or more, and tempered martensite in an area ratio of 5% or more. The ferrite has a mean grain size of 20.0 μm or less. An inverse intensity ratio of γ-fiber to α-fiber in the ferrite is 1.00 or more and an inverse intensity ratio of γ-fiber to α-fiber in the martensite and the tempered martensite is 1.00 or more. 213-. (canceled)15. The high-strength steel sheet according to claim 1 , wherein the high-strength steel sheet is a cold-rolled steel sheet.16. The high-strength steel sheet according to claim 14 , wherein the high-strength steel sheet is a cold-rolled steel sheet.17. The high-strength steel sheet according to claim 1 , wherein the high-strength steel sheet comprises a coating or plating on a surface thereof.18. The high-strength steel sheet according to claim 14 , wherein the high-strength steel sheet comprises a coating or plating on a surface thereof.19. The high-strength steel sheet according to claim 17 , wherein the coating or plating is a galvanized coating or plating.20. The high-strength steel sheet according to claim 18 , wherein the coating or plating is a galvanized coating or plating.21. A method for producing the high-strength steel sheet according to claim 1 , the method comprising:{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'heating a steel slab comprising the chemical composition as recited in to a temperature range of 1150° C. to 1300° C.;'}subjecting the steel slab to hot rolling with a finisher delivery temperature from 850° C. to 1000° C. to obtain a hot-rolled steel sheet;subjecting the hot-rolled steel sheet to coiling in a temperature range of 500° C. to 800° C.;subjecting the hot-rolled steel sheet to cold rolling at a cold rolling reduction of 40% or more to obtain a cold-rolled steel sheet;subjecting the cold-rolled steel sheet to first heat treatment, whereby the cold-rolled steel sheet is heated to a ...

HIGH STRENGTH STEEL SHEET AND MANUFACTURING METHOD THEREFOR

A high strength steel sheet having high strength such as a tensile strength of 780 MPa or more and having excellent blanking workability and stretch flangeability and a manufacturing method therefor are provided. A high strength steel sheet comprises: a chemical composition containing, in mass %, C: 0.05% to 0.30%, Si: 0.6% to 2.0%, Mn: 1.3% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 2.0% or less, N: 0.010% or less, and one or more of Ti, Nb, and V: 0.01% to 1.0% each, with a balance being Fe and incidental impurities; a ferrite microstructure of 50% or more in area ratio; an amount of precipitated Fe of 0.04 mass % or more; and a precipitate with a particle size of less than 20 nm, wherein C* and C*satisfy specific conditions. 1. A high strength steel sheet comprising:a chemical composition containing, in mass %,C: 0.05% to 0.30%,Si: 0.6% to 2.0%,Mn: 1.3% to 3.0%,P: 0.10% or less,S: 0.030% or less,Al: 2.0% or less,N: 0.010% or less, andone or more of Ti, Nb, and V: 0.01% to 1.0% each,with a balance being Fe and incidental impurities;a ferrite microstructure of 50% or more in area ratio; anda precipitate with a particle size of less than 20 nm,wherein Fe is precipitated in an amount of 0.04 mass % or more and{'sub': 'p', 'claim-text': [{'br': None, 'C*=([Ti]/48+[Nb]/93+[V]/51+[Mo]/96+[Ta]/181+[W]/184)×12\u2003\u2003(1)'}, {'br': None, 'sub': p', 'p', 'p', 'p', 'p', 'p', 'p, 'C*=([Ti]/48+[Nb]/93+[V]/51+[Mo]/96+[Ta]/181+[W]/184)×12\u2003\u2003(2)'}, {'br': None, 'C*≧0.035\u2003\u2003(3)'}, {'br': None, '−0.015≦[C]−C*≦0.03\u2003\u2003(4)'}, {'br': None, 'sub': 'p', 'C*/C*≧0.3\u2003\u2003(5)'}], 'C* defined by the following Expression (1) and C*defined by the following Expression (2) meet conditions of the following Expressions (3) to (5){'sub': p', 'p, 'where [M] denotes a content of an element M in the high strength steel sheet in mass %, and [M]denotes a content, with respect to the whole high strength steel sheet, of the element M contained in the precipitate ...

HOT STAMPED BODY

There is provided a hot stamped body including a middle part in sheet thickness and a surface layer arranged at both sides or one side of the middle part in sheet thickness, further including an intermediate layer formed between the middle part in sheet thickness and each surface layer so as to adjoin them, wherein the middle part in sheet thickness has a predetermined composition, the middle part in sheet thickness has a hardness of 500 Hv or more and 800 Hv or less, the surface layer has a hardness change ΔHin the sheet thickness direction of 100 Hv or more and less than 200 Hv, and the intermediate layer has a hardness change ΔHin the sheet thickness direction of 10 Hv or more and less than 50 Hv. 1. A hot stamped body comprising a middle part in sheet thickness; an intermediate layer; and a surface layer , the intermediate layer adjoining the middle part in sheet thickness and the surface layer ,wherein the middle part in sheet thickness comprises, by mass %,C: 0.20% or more and less than 0.70%Si: less than 3.00%,Mn: 0.20% or more and less than 3.00%,P: 0.10% or less,S: 0.10% or less,sol. Al: 0.0002% or more and 3.0000% or less,N: 0.01% or less, anda balance of Fe and unavoidable impurities,the middle part in sheet thickness has a hardness of 500 Hv or more and 800 Hv or less,{'sub': '1', 'the surface layer has a hardness change ΔHin the sheet thickness direction of 100 Hv or more and less than 200 Hv, and'}{'sub': '2', 'the intermediate layer has a hardness change ΔHin the sheet thickness direction of 10 Hv or more and less than 50 Hv.'}2. The hot stamped body according to claim 1 , wherein the Si content of the middle part in sheet thickness is 0.50% or less and the Mn content of the middle part in sheet thickness is 0.20% or more and less than 1.50%.3. The hot stamped body according to claim 1 , wherein the Si content of the middle part in sheet thickness is 0.50% or less and the Mn content of the middle part in sheet thickness is 1.50% or more and less than ...

STEEL SHEET FOR TOOL AND MANUFACTURING METHOD THEREFOR

The invention relates to a steel sheet for tool, and method for manufacturing thereof. An embodiment of the present invention is a steel sheet for a tool comprising 0.4 to 0.6 wt % of C, 0.05 to 0.5 wt % of Si, 0.1 to 1.5 wt % of Mn, 0.05 to 0.5 wt % of V, 0.1 to 2.0 wt % of at least of one or two components selected from the group comprising Ni, Cr, Mo, and combinations thereof, and the balance of Fe and inevitable impurities, with respect to 100 wt % of the total steel sheet, and provides a steel sheet for a tool of which the deviation of Rockwell hardness by the position in the width direction is within 5 HRC, and the ratio of those having a wave height in the longitudinal direction within 20 cm is 90% or more with respect to the wave height per 1 m of the steel sheet comprising the central portion in the longitudinal direction of the steel sheet for a tool. 1. A steel sheet for a tool comprising 0.4 to 0.6 wt % of C , 0.05 to 0.5 wt % of Si , 0.1 to 1.5 wt % of Mn , 0.05 to 0.5 wt % of V , 0.1 to 2.0 wt % of at least of one or two components selected from the group comprising Ni , Cr , Mo , and combinations thereof , and the balance of Fe and inevitable impurities , with respect to 100 wt % of the total steel sheet ,wherein the deviation of Rockwell hardness by the position in the width direction of the steel sheet for a tool is within 5 HRC,wherein the ratio of those having a wave height in the longitudinal direction within 20 cm is 90% or more with respect to the wave height per 1 m of the steel sheet comprising the central portion in the longitudinal direction of the steel sheet for a tool.2. The steel sheet for a tool of claim 1 , wherein the ratio of those having a wave height in the longitudinal direction within 10 cm is 90% or more with respect to the wave height per 1 m of the steel plate comprising the central portion in the longitudinal direction of the steel sheet for a tool.35-. (canceled)6. The steel sheet for a tool of claim 1 , wherein Mn: 0.1 to ...

Steel sheet for hardening, hardened member, and method for manufacturing steel sheet for hardening

An aspect of the present invention is a steel sheet for quench hardening, satisfying a prescribed composition and having a Mn concentration satisfying the formula (1): S1+S2<−10×[Mn]+44 (1), where [Mn] is Mn concentration in a steel sheet analyzed by inductively coupled plasma emission spectrography (% by mass); S1 is an area % of the region where the Mn concentration analyzed by an electron beam microprobe analyzer in the structure at a position of ¼ of the steel sheet thickness is two times or more the [Mn]; and S2 is an area % of the region where the Mn concentration analyzed by an electron beam microprobe analyzer in the structure at a position of ¼ of the steel sheet thickness is 0.5 times or less the [Mn].

HIGH-STRENGTH HIGH-TOUGHNESS THICK STEEL PLATE AND MANUFACTURING METHOD THEREFOR

The objective of one aspect of the present invention is to provide: a thick steel plate having high strength and high toughness without carrying out accelerated cooling using water cooling, in the manufacturing, by means of a thermomechanical control process (TMCP), of a thick steel having a thickness of 15 mmt and over; and a method for manufacturing the same. 1. A thick steel plate having high-strength and high-toughness , by weight % , comprising:0.02 to 0.10% of carbon (C), 0.6 to 1.7% of manganese (Mn), 0.5% or less of silicon (Si) (excluding 0%), 0.02% or less of phosphorus (P), 0.015% or less of sulfur (S), 0.005 to 0.05% of niobium (Nb), 0.005 to 0.08% of vanadium (V), a balance of iron (Fe) and inevitable impurities, and having a microstructure composed of ferrite and pearlite mixed structures,wherein a grain size of austenite is ASTM grain size number of 10 or more and a grain size of ferrite is ASTM grain size number of 9 or more.2. The thick steel plate having high-strength and high-toughness of claim 1 , wherein the thick steel plate further comprises claim 1 , by weight % claim 1 , one or more of 0.5% or less of Ni and 0.5% or less of Cr.3. The thick steel plate having high-strength and high-toughness of claim 1 , wherein the thick steel plate further comprises claim 1 , by weight % claim 1 , 0.05% or less of Ti.4. The thick steel plate having high-strength and high-toughness of claim 1 , wherein the thick steel plate comprises 85 to 95% of ferrite and 5 to 15% of pearlite by an area fraction.5. The thick steel plate having high-strength and high-toughness of claim 1 , wherein the thick steel plate has a yield ratio (yield strength (MPa)/tensile strength (MPa)) of 80 to 92% claim 1 , and impact toughness at −70° C. of 300 J or more.6. A manufacturing method of a thick steel plate having high-strength and high-toughness claim 1 , by weight % claim 1 , comprising steps of:reheating a steel slab including 0.02 to 0.10% of carbon (C), 0.6 to 1.7% of ...

STEEL SHEET

A steel sheet including an inner layer and a hard layer at one or both surfaces of the inner layer wherein the hard layer and the inner layer have predetermined compositions, each hard layer has a thickness of 20 μm or more and ⅖ of the total sheet thickness or less, the hard layer has an average micro-Vickers hardness of 400 HV or more and less than 700 HV, the hard layer has an N amount of 0.02% or less, the inner layer has an average micro-Vickers hardness of 80 HV or more and less than 400 HV, the inner layer has a carbide volume ratio of less than 2.00%, and the hard layer has a nanohardness standard deviation of 2.00 or less is provided. 13-. (canceled)4. A steel sheet comprising: an inner layer; and a hard layer , whereinthe hard layer comprises, by mass %,C: 0.08 to 0.40%,Si: 0.01 to 3.00%,Mn: 1.000 to 10.00%,P: 0.0001 to 0.0200%,S: 0.0001 to 0.0200%, anda balance of Fe and impurities, and optionally, by mass %,Al: 0.500% or less,N: 0.0200% or less,Cr: 2.000% or less,Mo: 1.000% or less,O: 0.0200% or less,Ti: 0.500% or less,B: 0.0100% or less,Nb: 0.500% or less,V: 0.500% or less,Cu: 0.500% or less,W: 0.100% or less,Ta: 0.100% or less,Ni: 0.500% or less,Sn: 0.050% or less,Sb: 0.050% or less,As: 0.050% or less,Mg: 0.0500% or less,Ca: 0.050% or less,Y: 0.050% or less,Zr: 0.050% or less,La: 0.050% or less, andCe: 0.050% or less,the inner layer comprises, by mass %,C: 0.001 to 0.200%,Si: 0.01 to 3.00%,Mn: 0.20 to 3.00%,P: 0.0001 to 0.0200%,S: 0.0001 to 0.0200%, anda balance of Fe and impurities, and optionally, by mass %,Al: 0.500% or less,N: 0.0200% or less,Cr: 2.000% or less,Mo: 1.000% or less,O: 0.0200% or less,Ti: 0.500% or less,B: 0.0100% or less,Nb: 0.500% or less,V: 0.500% or less,Cu: 0.500% or less,W: 0.100% or less,Ta: 0.100% or less,Ni: 0.500% or less,Sn: 0.050% or less,Sb: 0.050% or less,As: 0.050% or less,Mg: 0.0500% or less,Ca: 0.050% or less,Y: 0.050% or less,Zr: 0.050% or less,La: 0.050% or less, andCe: 0.050% or lessthe hard layer has a thickness ...

METHOD AND DEVICE FOR COOLING A STEEL STRIP TRAVELLING IN A CONTINUOUS LINE COOLING SECTION

Process and device for cooling a steel strip () running through the cooling section () of a continuous line, whereby cooling is achieved by projecting the strip with an aqueous solution of formic acid with a concentration of formic acid between 0.1% and 6%, and preferably between 0.5% and 2%. 112. Cooling process for a steel strip () running through the cooling section () of a continuous line , including a projection onto the said strip of a projecting solution , said solution being a liquid or a mixture of a liquid solution and a gas , characterized by the said liquid solution having a formic acid concentration of between 0.1% and 6% by mass.2. Process as per claim 1 , where the liquid solution has a formic acid concentration of between 0.5% and 2% by mass.3. Process as per claim 1 , where the solution is projected onto the steel strip by spraying.413. Process as per claim 1 , also including a continuous or periodic check of the solution to be projected claim 1 , said check including a measurement of at least one physico-chemical datum of the said solution—from the group including pH claim 1 , density and formic acid concentration claim 1 , or a combination of these physico-chemical data claim 1 , and claim 1 , when this measurement does not fall within a predetermined range of tolerance claim 1 , a predetermined volume of the projected solution is drawn off and the same predetermined volume of a formic acid solution is injected into the projection unit () claim 1 , said predetermined volume of formic acid solution having a concentration of formic acid such that the liquid solution to be projected claim 1 , following the injection claim 1 , is of a concentration of formic acid between 0.1% and 6%.5. Process as per claim 4 , where the liquid solution to be projected following the injection has a formic acid concentration between 0.5% and 2% by mass.6. Process as per claim 1 , where the solution drawn off is treated through oxidation with oxygenated water claim 1 , ...

STEEL SHEET AND MANUFACTURING METHOD THEREFOR

This steel sheet has a predetermined chemical composition, in which a steel structure of an inside of the steel sheet contains, by volume fraction, soft ferrite: 0% to 30%, retained austenite: 3% to 40%, fresh martensite: 0% to 30%, a sum of pearlite and cementite: 0% to 10%, and a remainder includes hard ferrite, a number proportion of the retained austenite having an aspect ratio of 2.0 or more in the total retained austenite is 50% or more, a soft layer having a thickness of 1 to 100 μm from a surface in a sheet thickness direction is present, in ferrite contained in the soft layer, a volume fraction of grains having an aspect ratio of 3.0 or more is 50% or more, a volume fraction of retained austenite in the soft layer is 80% or less of the volume fraction of the retained austenite in the inside of the steel sheet, and a peak of an emission intensity at a wavelength indicating Si appears in a range of more than 0.2 μm and 10.0 μm or less from the surface. 19-. (canceled)10. A steel sheet comprising , as a chemical composition , by mass %:C: 0.050% to 0.500%;Si: 0.01% to 3.00%;Mn: 0.50% to 5.00%;P: 0.0001% to 0.1000%;S: 0.0001% to 0.0100%;Al: 0.001% to 2.500%;N: 0.0001% to 0.0100%;O: 0.0001% to 0.0100%;Ti: 0% to 0.300%;V: 0% to 1.00%;Nb: 0% to 0.100%;Cr: 0% to 2.00%;Ni: 0% to 2.00%;Cu: 0% to 2.00%;Co: 0% to 2.00%;Mo: 0% to 1.00%;W: 0% to 1.00%;B: 0% to 0.0100%;Sn: 0% to 1.00%;Sb: 0% to 1.00%;Ca: 0% to 0.0100%;Mg: 0% to 0.0100%;Ce: 0% to 0.0100%;Zr: 0% to 0.0100%;La: 0% to 0.0100%;Hf: 0% to 0.0100%;Bi: 0% to 0.0100%;REM: 0% to 0.0100%; anda remainder including Fe and impurities, a soft ferrite: 0% to 30%,', 'a retained austenite: 3% to 40%,', 'a fresh martensite: 0% to 30%,', 'a sum of pearlite and cementite: 0% to 10%, and', 'a remainder includes hard ferrite,, 'wherein a steel structure in a ⅛ to ⅜ thickness range centered on a ¼ thickness position from a surface contains, by volume fraction,'}in the ⅛ to ⅜ thickness range, a number proportion of the retained ...

ALLOYED HOT-DIP GALVANIZED STEEL SHEET AND ALLOYED HOT-DIP GALVANIZED STEEL SHEET PRODUCTION METHOD

In one aspect of the present invention, a hot-dip galvannealed steel sheet includes a steel sheet and a hot-dip galvannealed layer on the surface of the steel sheet. The steel sheet has a predetermined composition and has an average oxygen concentration of 0.10 mass % or less in the region of 1 μm from the interface between the steel sheet and the hot-dip galvannealed layer toward the steel sheet. The metal microstructure of the steel sheet at a position of t/4 where t represents the sheet thickness of the hot-dip galvannealed steel sheet includes 50 to 85 area % of martensite, 15 to 50 area % of bainite, and 5 area % or less of ferrite. 1. A hot-dip galvannealed steel sheet comprising:a steel sheet; and a hot-dip galvannealed layer on a surface of the steel sheet, wherein the steel sheet comprises, in mass %,C: 0.10% or more and 0.25% or less,Si: more than 0% and 0.50% or less,Mn: more than 2.0% and 3.5% or less,P: more than 0% and 0.1% or less,S: more than 0% and 0.05% or less,Al: 0.01% or more and 0.10% or less,Ti: more than 0% and 0.1% or less,B: 0.0020% or more and 0.0050% or less,N: more than 0?/ and 0.01% or less,Cr: more than 0% and 0.5% or less, andMo: more than 0% and 0.5% or less,Wherein the steel sheet has an average oxygen concentration of 0.10 mass % or less in a region of 1 μm from an interface between the steel sheet and the hot-dip galvannealed layer toward the steel sheet, andwherein a metal microstructure of the steel sheet at a position of t/4, where t represents a sheet thickness of the hot-dip galvannealed steel sheet, comprises 50 to 85 area % of martensite, 15 to 50 area % of bainite, and 5 area % or less of ferrite.2. A method for manufacturing the hot-dip galvannealed steel sheet of claim 1 , the method comprising:{'b': '1100', 'soaking a steel having a composition of the steel sheet at ° C. to 1300° C., hot-rolling the steel at a finishing temperature of 850° C. to 950° C., and coiling the hot-rolled steel at 630° C. to 680° C., to provide ...

METAL SHEET, METHOD OF PRODUCING METAL SHEET, METHOD OF PRODUCING MOLDED PRODUCT OF METAL SHEET, AND MOLDED PRODUCT OF METAL SHEET

Provided are a metal sheet, a method of producing a metal sheet, a method of producing a molded product of a metal sheet, and a molded product of a metal sheet, in which occurrence of surface roughness is inhibited. Provided are a metal sheet satisfying conditions (a1), (b1) or (c1) at the surface and a method for producing the metal sheet. Also provided are a method for producing a molded product of a metal sheet using the metal sheet, and a molded product of the metal sheet. (a1) The area fraction of crystal grains having a crystal orientation divergent by 20° or more from a (111) plane and by 20° or more from a (001) plane is from 0.25 to 0.35, and the average crystal grain size is less than 16 μm. (b1) The area fraction of crystal grains having a crystal orientation divergent by 20° or more from a (111) plane and by 20° or more from a (001) plane is from 0.15 to 0.30, and the average crystal grain size is 16 μm or more. (c1) The area fraction of crystal grains with a Taylor Factor value from 3.0 to 3.4, when assuming plane strain tensile deformation in the transverse direction, is from 0.18 to 0.40. 123-. (canceled)24. A metal sheet having a bcc structure and satisfying the following condition (a1) or (b1) at a surface thereof:(a1) an area fraction of crystal grains having a crystal orientation divergent by 20° or more from a (111) plane parallel to a surface of the metal sheet and by 20° or more from a (001) plane is from 0.25 to 0.35, and an average crystal grain size is less than 16 μm; or(b1) an area fraction of crystal grains having a crystal orientation divergent by 20° or more from a (111) plane parallel to a surface of the metal sheet and by 20° or more from a (001) plane is from 0.15 to 0.30, and an average crystal grain size is 16 μm or more,wherein the metal sheet is a steel sheet;wherein the steel sheet is a ferrite-based steel sheet having a chemical composition of:C: from 0.0040% by mass to 0.0100% by mass;Si: from 0% by mass to 1.0% by mass;Mn: ...

Roller hearth furnace and method for the heat treatment of metal sheets

The invention relates to a roller hearth furnace for the heat treatment of coated metal sheets as well as to a corresponding method. The objective of the invention is to put forward a roller hearth furnace that allows the alternating processing of AlSi-coated metal sheets and metal sheets with zinc alloy coatings for hot-working, whereby considerably less effort is involved for the alternating procedure than is the case in the state of the art. The roller hearth furnace according to the invention for the heat treatment of coated metal parts is characterized in that it has at least a first zone and a second zone, whereby in the first zone, a temperature below the melting temperature of the AlSi deposits or a temperature of more than approximately 900° C. [1652° F.] can be maintained, whereas in the second zone, a temperature of more than approximately 870° C. [1598° F.] can be reached.

HIGH-STRENGTH STEEL SHEET AND PRODUCTION METHOD THEREFOR

A steel sheet has a microstructure that contains ferrite in an area ratio of 20% or more, martensite in an area ratio of 5% or more, and tempered martensite in an area ratio of 5% or more. The ferrite has a mean grain size of 20.0 μm or less. An inverse intensity ratio of γ-fiber to α-fiber in the ferrite is 1.00 or more and an inverse intensity ratio of γ-fiber to α-fiber in the martensite and the tempered martensite is 1.00 or more. 1. A high-strength steel sheet comprising:a chemical composition that contains, by mass %, C: 0.060% or more and 0.200% or less, Si: 0.50% or more and 2.20% or less, Mn: 1.00% or more and 3.00% or less, P: 0.100% or less, S: 0.0100% or less, Al: 0.010% or more and 2.500% or less, N:212-. (canceled)14. The high-strength steel sheet according to claim 1 , wherein the high-strength steel sheet is a cold-rolled steel sheet.15. The high-strength steel sheet according to claim 13 , wherein the high-strength steel sheet is a cold-rolled steel sheet.16. The high-strength steel sheet according to claim 1 , wherein the high-strength steel sheet comprises a coating or plating on a surface thereof.17. The high-strength steel sheet according to claim 13 , wherein the high-strength steel sheet comprises a coating or plating on a surface thereof.18. The high-strength steel sheet according to claim 16 , wherein the coating or plating is a galvanized coating or plating.19. The high-strength steel sheet according to claim 17 , wherein the coating or plating is a galvanized coating or plating.20. A method for producing the high-strength steel sheet according to claim 1 , the method comprising:{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'heating a steel slab comprising the chemical composition as recited in to a temperature range of 1150° C. to 1300° C.;'}subjecting the steel slab to hot rolling with a finisher delivery temperature from 850° C. to 1000° C. to obtain a hot-rolled steel sheet;subjecting the hot-rolled steel sheet to coiling in a ...

STEEL SHEET

A steel sheet includes: a base iron; a scale of 10.0 μm or less in thickness on a surface of the base iron; a subscale between the base iron and the scale. In the subscale, an average value of Cr concentrations is 1.50 mass % to 5.00 mass %, and one part or more exist(s) where a ratio of Cr concentrations between two adjacent measurement regions separate by 1 μm is 0.90 or less or 1.11 or more in a range of 50 μm in length in a rolling direction. A percentage of an amount of Ti contained in carbide or carbonitride of 100 nm or more and 1 μm or less in grain diameter to a parameter Tirepresented by a formula “Ti=[Ti]−48/14[N]” is 30% or less in which [Ti] denotes a Ti content (mass %) and [N] denotes a N content (mass %). 13-. (canceled)4. A steel sheet comprising:a base iron;a scale of 10.0 μm or less in thickness on a surface of the base iron; anda subscale between the base iron and the scale,wherein the base iron comprises a chemical composition represented by, in mass %,C: 0.05% to 0.20%,Si: 0.01% to 1.50%,Mn: 1.50% to 2.50%,P: 0.05% or less,S: 0.03% or less,Al: 0.005% to 0.10%,N: 0.008% or less,Cr: 0.30% to 1.00%,Ti: 0.06% to 0.20%,Nb: 0.00% to 0.10%,V: 0.00% to 0.20%,B: 0.0000% to 0.0050%,Cu: 0.00% to 0.50%,Ni: 0.00% to 0.50%,Mo: 0.00% to 0.50%,W: 0.00% to 0.50%,Ca: 0.0000% to 0.0050%,Mg: 0.0000% to 0.0050%,REM: 0.000% to 0.010%, andthe balance: Fe and impurities,{'sub': 'eff', 'wherein, in the base iron, a percentage of an amount of Ti contained in carbide or carbonitride of 100 nm or more and 1 μm or less in grain diameter to a parameter Tirepresented by a following formula 1 is 30% or less, [Ti] denoting a Ti content (mass %) and [N] denoting a N content (mass %) in the following formula 1,'} an average value of Cr concentrations is 1.50 mass % to 5.00 mass %, wherein the average value of Cr concentrations is an average value Ave of maximum values Cmax among 50 or more measurement regions, each of the 50 or more measurement regions is made of 10 measurement ...

ORIENTED ELECTRICAL STEEL SHEET AND METHOD FOR MANUFACTURING SAME

An embodiment of the present invention provides a grain-oriented electrical steel sheet, including a groove including a bottom portion and a side portion positioned on a surface of the electrical steel sheet, a metal oxide layer positioned on the groove, and an insulating layer positioned on the metal oxide layer, wherein the steel sheet includes a normal groove in which thicknesses of the metal oxide layer positioned on the bottom portion and the side portion exceed 0.5 μm, and a defective groove in which thicknesses of the metal oxide layer positioned on the bottom portion and the side portion are 0.5 μm or less, the insulating layer positioned on the normal groove has a thickness of 0.5 μm to 1.5 μm, and the insulating layer positioned on the defective groove has a thickness of 1.5 to 10 μm. 1. A grain-oriented electrical steel sheet , comprisinga groove including a bottom portion and a side portion and positioned on a surface of the electrical steel sheet,a metal oxide layer positioned on the groove, andan insulating layer positioned on the metal oxide layer,wherein the steel sheet includes a normal groove in which thicknesses of the metal oxide layer positioned on the bottom portion and the side portion exceed 0.5 μm, and a defective groove in which thicknesses of the metal oxide layer positioned on the bottom portion and the side portion are 0.5 μm or less,the insulating layer positioned on the normal groove has a thickness of 0.5 μm to 4.0 μm, andthe insulating layer positioned on the defective groove has a thickness of 1.5 to 10 μm.2. The grain-oriented electrical steel sheet of claim 1 , whereinthe defective groove includes a side defective groove having a defective portion on the side portion and a bottom defective groove having a defective portion on the bottom portion,the insulating layer positioned on the side defective groove has a thickness of 1.5 to 6 μm, andthe insulating layer positioned on the bottom defective groove has a thickness of 2.0 to 10 μ ...

HIGH STRENGTH STEEL SHEET HAVING EXCELLENT DUCTILITY AND WORKABILITY, AND METHOD FOR MANUFACTURING SAME

Provided is a steel sheet that can be used for automobile parts or the like, and relates to a steel sheet having an excellent balance of strength and ductility, and excellent workability, and a method for manufacturing same. 1. A high-strength steel sheet comprising , by weight % , carbon (C): more than 0.25% to 0.75% , silicon (Si): 4.0% or less , manganese (Mn): 0.9 to 5.0% , aluminum (Al): 5.0% or less , phosphorus (P): 0.15% or less , sulfur (S): 0.03% or less , nitrogen (N): 0.03% or less , and a balance of iron (Fe) and inevitable impurities ,wherein a microstructure comprises tempered martensite, bainite, and retained austenite, and {'br': None, 'i': 'av≤', '0.55≤[Si+Al]γ/[Si+Al]0.85,\u2003\u2003[Relational Expression 1]'}, 'wherein the high-strength steel sheet satisfies the following Relational Expression 1,'}where [Si+Al]γ is a content (weight %) of Si and Al contained in the retained austenite, and [Si+Al]av is a content (weight %) of Si and Al contained in the high-strength steel sheet.2. The high-strength steel sheet of claim 1 , further comprising at least one of (1) to (9):(1) at least one of titanium (Ti): 0 to 0.5%, niobium (Nb): 0 to 0.5%, and vanadium (V): 0 to 0.5%(2) at least one of chromium (Cr): 0 to 3.0% and molybdenum (Mo): 0 to 3.0%(3) at least one of copper (Cu): 0 to 4.5% and nickel (Ni): 0 to 4.5%(4) boron (B): 0 to 0.005%(5) at least one of calcium (Ca): 0 to 0.05%, a rare earth element (REM) except yttrium (Y): 0 to 0.05%, and magnesium (Mg): 0 to 0.05%(6) at least one of tungsten (W): 0 to 0.5% and zirconium (Zr): 0 to 0.5%(7) at least one of antimony (Sb): 0 to 0.5% and tin (Sn): 0 to 0.5%(8) at least one of yttrium (Y): 0 to 0.2% and hafnium (Hf): 0 to 0.2%(9) cobalt (Co): 0 to 1.5%.3. The high-strength steel sheet of claim 1 , wherein a sum of silicon and aluminum (Si+Al) is 1.0 to 6.0%.4. The high-strength steel sheet of claim 1 , wherein the microstructure of the steel sheet comprises claim 1 , by volume % claim 1 , 30 to 75% of ...

Pressure vessel steel having excellent hydrogen induced cracking resistance, and manufacturing method therefor

The present invention relates to pressure vessel steel having excellent hydrogen-induced cracking resistance, and a manufacturing method therefor. One embodiment of the present invention provides a pressure vessel steel having excellent hydrogen-induced cracking resistance, and a manufacturing method therefor, the steel comprising, by wt %, 0.2-0.3% of carbon (C), 0.05-0.50% of silicon (Si), 0.03% or less of manganese (Mn), 0.005-0.1% of aluminum (Al), 0.010% or less of phosphorus (P), 0.0015% or less of sulfur (S), 0.001-0.03% of niobium (Nb), 0.001-0.03% of vanadium (V), 0.001-0.03% of titanium (Ti), 0.01-0.20% of chromium (Cr), 0.01-0.15% of molybdenum (Mo), 0.01-0.50% of copper (Cu), 0.05-0.50% of nickel (Ni), 0.0005-0.0040% of calcium (Ca), and the balance of Fe and other inevitable impurities, wherein the average grain size of ferrite is 5-15 μm.

STEEL FOR HIGH-STRENGTH ALUMINUM CLAD SUBSTRATE AND MANUFACTURING METHOD THEREFOR

A steel for high-strength aluminum clad substrate, comprising the following chemical elements by mass percent: C: 0.008-0.02%, 0 Подробнее

HOT-ROLLED STEEL SHEET

A hot-rolled steel sheet according to the present invention has a predetermined chemical composition, in which, when a height profile of a surface of the hot-rolled steel sheet is measured in each of five measurement ranges in a rolling direction and a direction perpendicular to the rolling direction, a distance in a height direction from an average height position which is an average of a height position of a point having a highest height position and a height position of a recessed part which is a point having a lowest height position to the recessed part is indicated as R(μm) in each of the height profiles, and an average of heights of two measurement points away from the recessed part in the rolling direction or the direction perpendicular to the rolling direction by 5 μm is indicated as R(μm), an average value of radii of curvature r represented by Expression (1) is 10 μm or more, and a tensile strength of the hot-rolled steel sheet is 500 MPa or more. r=(25+|R−R|)/2|R−R| . . . (1) 1. A hot-rolled steel sheet comprising , as a chemical composition , by mass %:C: 0.030% to 0.250%;Si: 0.05% to 2.50%;Mn: 1.00% to 4.00%;Sol. Al: 0.001% to 2.000%;P: 0.100% or less;S: 0.0200% or less;N: 0.01000% or less;Ti: 0% to 0.20%;Nb: 0% to 0.20%;B: 0% to 0.010%;V: 0% to 1.0%;Cr: 0% to 1.0%;Mo: 0% to 1.0%;Cu: 0% to 1.0%;Co: 0% to 1.0%;W: 0% to 1.0%;Ni: 0% to 1.0%;Ca: 0% to 0.01%;Mg: 0% to 0.01%;REM: 0% to 0.01%;Zr: 0% to 0.01%; anda remainder consisting of Fe and impurities,{'sub': 1', '2, 'wherein, when a height profile of a surface of the hot-rolled steel sheet is measured in each of five measurement ranges in a rolling direction and a direction perpendicular to the rolling direction, a distance in a height direction from an average height position which is an average of a height position of a point having a highest height position and a height position of a recessed part which is a point having a lowest height position to the recessed part is indicated as R(μm) in each of the ...

COLD-ROLLED STEEL SHEET

The cold-rolled steel sheet having a high bake hardening amount and excellent bendability after bake hardening according to the present invention has a predetermined composition, and contains 20% or more and 70% or less of ferrite and 30% or more of tempered martensite in terms of area ratio, in which a sum of ferrite and tempered martensite is 90% or more, and in a case where a microstructure image of 30 μm×30 μm obtained by photographing a structure at a magnification of 2,000-fold is disposed in an xy coordinate system having a sheet thickness direction as an x-axis and a rolling direction as a y-axis, the microstructure image is divided into 1024 pieces in an x-axis direction and 1024 pieces in a y-axis direction to form 1024×1024 divided regions, and a two-dimensional image is created by performing double gradation by assuming a value of “1” in each of the divided regions in one case where the structure is ferrite and assuming a value of “0” in the other cases, a heterogeneity α when two-dimensional discrete Fourier transform is performed on the two-dimensional image is 1.20 or less. 2. The cold-rolled steel sheet according to claim 1 , further comprising claim 1 , by mass % claim 1 , one or two or more of;Ti: 0.003% to 0.100%,Nb: 0.003% to 0.100%, andV: 0.003% to 0.100%, in a total amount of 0.100% or less.3. The cold-rolled steel sheet according to claim 1 ,wherein the microstructure image is a microstructure image of 30 μm×30 μm obtained by photographing a structure at a position from ¼ to ⅜ of the sheet thickness from the surface of the cold-rolled steel sheet in a sheet thickness cross section perpendicular to the sheet width direction of the steel sheet at a center position of the sheet width of the cold-rolled steel sheet, at a magnification of 2,000-fold.4. The cold-rolled steel sheet according to claim 2 ,wherein the microstructure image is a microstructure image of 30 μm×30 μm obtained by photographing a structure at a position from ¼ to ⅜ of the ...

HOT ROLLED AND UNANNEALED FERRITIC STAINLESS STEEL SHEET HAVING EXCELLENT IMPACT TOUGHNESS, AND MANUFACTURING METHOD THEREFOR

A non-annealed hot-rolled ferritic stainless steel sheet with excellent impact toughness includes, in percent (%) by weight of the entire composition, C: more than 0 and 0.03% or less, Si: 0.1 to 0.5%, Mn: 1.5% or less, P: 0.04% or less, Cr: 10.5 to 14%, Ni: more than 0 and 1.5% or less, Ti: 0.01 to 0.5%, Cu: more than 0 and 1.0% or less, N: more than 0 and 0.015% or less, Al: 0.1% or less, the remainder of iron (Fe) and other inevitable impurities, and satisfies the following equation (1), and the average grain size of the cross-sectional microstructure in the direction perpendicular to the rolling direction is 60 μm or less. 1. A non-annealed hot-rolled ferritic stainless steel sheet with excellent impact toughness , the ferritic stainless steel comprising , in percent (%) by weight of the entire composition , C: more than 0 and 0.03% or less , Si: 0.1 to 0.5% , Mn: 1.5% or less , P: 0.04% or less , Cr: 10.5 to 14% , Ni: more than 0 and 1.5% or less , Ti: 0.01 to 0.5% , Cu: more than 0 and 1.0% or less , N: more than 0 and 0.015% or less , Al: 0.1% or less , the remainder of iron (Fe) and other inevitable impurities , and {'br': None, '1500≤(1001.5*C+950.6*Mn+1350.5*Ni+395.6*Cu−0.7*Si−1.0*Ti−0.1*Cr−1.0*P−1.0*Al+1020.5*N)≤2200\u2003\u2003(1)'}, 'satisfying the following equation (1), and the average grain size of the cross-sectional microstructure in the direction perpendicular to the rolling direction is 60 μm or less.'}(Here, C, Mn, Ni, Cu, Si, Ti, Cr, P, Al and N mean the content (% by weight) of each element).2. The ferritic stainless steel sheet according to claim 1 , wherein the non-annealed hot-rolled steel sheet has a thickness of 6.0 to 25.0 mm.3. The ferritic stainless steel sheet according to claim 1 , wherein the −20° C. Charpy impact energy is 150 J/cmor more.4. The ferritic stainless steel sheet according to claim 1 , wherein the average size of grains having a misorientation between grains of the microstructure of 15 to 180° is 60 um or less.5. The ...

Abrasion resistant steel having excellent hardness and impact toughness and manufacturing method therefor

One embodiment of the present disclosure provides an abrasion resistant steel having excellent hardness and impact toughness, and a manufacturing method therefor, the steel comprising, by wt %, 0.33-0.42% of C, 0.1-0.7% of Si, 0.6-1.6% of Mn, 0.05% or less of P, 0.02% or less of S, 0.07% or less of Al, 0.55-5.0% of Ni, 0.01-1.5% of Cu, 0.01-0.8% of Cr, 0.01-0.8% of Mo, 50 ppm or less of B, and 0.02% or less of Co, further comprising one or more selected from the group consisting of 0.02% or less of Ti, 0.05% or less of Nb, 0.05% or less of V and 2-100 ppm of Ca, and comprising the balance of Fe and other inevitable impurities, wherein C and Ni satisfy the following relation 1, and the microstructure comprises 95 area % or more of martensite and 5% or less of bainite (including 0%). [Relation 1] [C]×[Ni]≥0.231

GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND METHOD FOR PRODUCING SAME

When a steel material is processed to produce a grain-oriented electrical steel sheet, conditions of a decarburization annealing process and conditions of a process before the decarburization annealing are adjusted so that a difference in concentration of O, Si, Al, Mn and P between the front and back surfaces of the steel sheet after the decarburization annealing is within a given range with respect to an average concentration between the front and back surfaces, and hence the difference in concentration of each of O, Si and Mg between the front and back surfaces of the product sheet is within ±5%, the difference in concentration of one or more of Al, Mn and P between the front and back surfaces is within ±15% and the difference in the concentration of one or more of Ca and Ti between the front and back surfaces is within ±20%. 1. A grain-oriented electrical steel sheet having a ceramic underlaying coating on the steel sheet surface , characterized in that (1) each of O, Si and Mg: within ±5%,', '(2) one or more of Al, Mn and P: within ±15%,', '(3) one or more of Ca and Ti: within ±20%., 'differences in concentrations of O, Si, Mg, Al, Mn, P, Ca and Ti between the front and back surfaces of the underlaying coating satisfies the following conditions (1), (2) and (3) with respect to each average concentration between the front and back surfaces2. A method for producing a grain-oriented electrical steel sheet comprising:hot rolling a steel material for a grain-oriented electrical steel sheet to form a hot-rolled sheet,after a hot-band annealing or without a hot-band annealing, subjecting the hot-rolled sheet to one cold rolling or two or more cold rollings having an intermediate annealing interposed therebetween to form a cold-rolled sheet having a final sheet thickness,subjecting the cold-rolled sheet to a decarburization annealing combined with a primary recrystallization annealing,applying an annealing separator composed mainly of MgO thereon,subjecting the cold- ...

HIGH-STRENGTH GALVANIZED STEEL SHEET HAVING EXCELLENT ELECTRICAL RESISTANCE SPOT WELDABILITY, AND METHOD FOR PRODUCING SAME

Provided is a galvanized steel sheet having excellent spot weldability; and a method for producing same. The galvanized steel sheet includes a base steel sheet and a zinc-based plating layer formed on the base steel sheet, wherein the surface layer of the base steel sheet may have a decarburization rate of at least 30% as represented by equation 1. [Equation 1]: Decarburization rate (%) of surface layer=(1−average carbon concentration in surface layer/bulk carbon concentration)*100, where the surface layer refers to a region extending to a depth of 35 μm from the surface of the base steel sheet. 1. A galvanized steel sheet including a base steel sheet and a zinc-based plating layer formed on the base steel sheet , {'br': None, 'Decarburization ratio(%)of surface layer=(1−average carbon concentration in surface layer/bulk carbon concentration)*100'}, 'wherein a surface layer of the base steel sheet has a decarburization ratio of 30% or more, represented by equation 1 as below.'}where the surface layer refers to a region up to a depth of 35 μm from the surface of the base steel sheet.2. The galvanized steel sheet of claim 1 , wherein the decarburization ratio of the surface layer is 40% or more.3. The galvanized steel sheet of claim 1 , wherein tensile strength of the steel sheet is 490 Mpa or more.4. The galvanized steel sheet of claim 1 , wherein a coating amount of the zinc-based plating layer is 30-70 g/m.5. The galvanized steel sheet of claim 1 , wherein the zinc-based plating layer is a hot-dip galvannealed (GA) layer having a degree of alloying of 8-13 weight %.6. The galvanized steel sheet of claim 1 , wherein the steel sheet has a composition including 0.05-1.5% of C claim 1 , 2.0% or less of Si claim 1 , 1.0-30% of Mn claim 1 , 3% or less of S—Al (acid-soluble aluminum) claim 1 , 2.5% or less of Cr claim 1 , 1% or less of Mo claim 1 , 0.005% or less of B claim 1 , 0.2% or less of Nb claim 1 , 0.2% or less of Ti claim 1 , 0.2% or less of V claim 1 , 0.1% or ...