КОРРОЗИОННО-СТОЙКАЯ СТАЛЬ, СПОСОБ ИЗГОТОВЛЕНИЯ УКАЗАННОЙ СТАЛИ И ЕЕ ПРИМЕНЕНИЕ

Изобретение относится к области металлургии, а именно к коррозионно-стойкой стали с пределом по меньшей мере 758 МПа. Сталь содержит, вес.%: 0,005≤C<0,03, 14≤Cr≤17, 2,3≤Mo≤3,5, 3,2≤Ni≤4,5, Si≤0,6, 0,5≤Cu≤1,5, 0,4≤Mn≤1,3, 0,35≤V≤0,6, 3,2xC≤Nb≤0,1, W≤1,5, 0,5≤Co≤1,5, 0,02≤N≤0,05, Ti≤0,05, P≤0,03, S≤0,005, Al≤0,05, остальное - Fe и неизбежные примеси. Сталь имеет микроструктуру, содержащую от 5% до 15% аустенита. Сталь обладает высокой коррозионной стойкостью и сопротивлением на излом, а также легко изготавливается в условиях воздействия высокой температуры. 3 н. и 10 з.п. ф-лы, 4 табл.

СПОСОБ ИЗГОТОВЛЕНИЯ ГОРЯЧЕФОРМОВАННОЙ СТАЛЬНОЙ ДЕТАЛИ И ГОРЯЧЕФОРМОВАННАЯ СТАЛЬНАЯ ДЕТАЛЬ

Изобретение относится к области металлургии. Для улучшения формовочной способности стального материала с обеспечением минимальной прочности на разрыв изготовление детали осуществляют путем горячей формовки начального продукта из стали, причем начальный продукт нагревают до температуры выше 60°С и ниже температуры превращения Acи затем выполняют формовку в данном температурном диапазоне, причем деталь имеет минимальную прочность на разрыв 700 МПа и высокое удлинение при разрушении, при этом начальный продукт имеет следующий состав стали в мас.%: С: от 0,0005 до 0,9; Mn: от более 3,0 до 12; при этом остаток – железо с неизбежными сопутствующими стали элементами, при легировании в качестве опции по меньшей мере один из следующих элементов (в мас.%): Al до 10; Si до 6; Cr до 6; Nb до 1,5; V до 1,5; Ti до 1,5; Mo до 3; Cu до 3; Sn до 0,5; W до 5; Co до 8; Zr до 0,5; Ta до 0,5; Te до 0,5; B до 0,15; P макс. 0,1, в частности < 0,04; S макс 0,1, в частности < 0,02; N макс. 0,1, в частности < 0,05 ...

ДОРН ДЛЯ ЭЛЕКТРОМЕХАНИЧЕСКОЙ ЗАКАЛКИ ЦИЛИНДРИЧЕСКИХ ОТВЕРСТИЙ ДЕТАЛЕЙ

Полезная модель относится к машиностроению, в частности к инструментальной оснастке для поверхностного упрочнения и может быть использована при упрочнении цилиндрических отверстий деталей. Дорн для электромеханической закалки цилиндрических отверстий деталей включает оправку со сферическим углублением, стяжные гайки, токоизоляционную втулку под конус Морзе и шарообразный упрочняюще-калибрующий элемент. В нижней торцевой части оправки выполнено сферическое углубление. Поверхность упрочняюще-калибрующего элемента и сферическое углубление в нижней торцевой части оправки образуют шарнирное соединение. В верхней торцевой части оправки выполнено осевое глухое отверстие, герметично заглушенное винтовой пробкой. В средней части оправки, ниже стяжных гаек, выполнено радиальное глухое отверстие, сообщающееся с осевым отверстием, и установлен штуцер. В нижней части оправки на внешней стороне выполнено два симметричных друг другу канала для подвода технологической жидкости к сопрягаемым поверхностям ...

СТАЛЬНАЯ ТРУБКА ДЛЯ ТОПЛИВОПРОВОДА ВЫСОКОГО ДАВЛЕНИЯ И СПОСОБ ЕЕ ПРОИЗВОДСТВА

Изобретение относится к двигателестроению, в частности к топливной аппаратуре дизельных двигателей внутреннего сгорания. Заявленное изобретение обеспечивает увеличенный срок службы, стойкость к усталостному разрушению и высокую надежность путем обеспечения высокого критического внутреннего давления, при котором не возникает растрескивание, при высокой прочности материала. Стальная трубка для топливопровода высокого давления содержит (в массовых процентах) С: 0,12-0,27%; Si: 0,05-0,40%; Mn: 0,8-2,0%; остальное - Fe и примеси, при этом примеси содержат Са: 0,001% или менее, Р: 0,02% или менее и S: 0,01% или менее, причем предел прочности на разрыв составляет не менее 900 Н/мм2 и максимальный диаметр имеющихся неметаллических включений в пределах глубины по меньшей мере 20 мкм от внутренней поверхности стальной трубки не превышает 20 мкм. Далее стальная трубка может содержать один или более из следующих элементов: Сr 1% или менее, Мо 1% или менее, Ti 0,04% или менее, Nb 0,04% или менее и V ...

Способ изготовления трубных изделий из циркониевого сплава

Изобретение относится к изготовлению трубных изделий из циркониевого сплава. Осуществляют выплавку слитка многократным вакуумно-дуговым переплавом, механическую обработку слитка, нагрев, горячую многостадийную ковку с получением поковки, термическую обработку поковки и последующую механическую обработку поковки с получением трубных заготовок. Осуществляют проведение вакуумной термической обработки трубных заготовок, нанесение на них защитного покрытия и нагрев до температуры горячего прессования, горячее прессование, удаление защитного покрытия, вакуумную термическую обработку, многократную холодную прокатку с промежуточными вакуумными термическими обработками с получением трубных изделий. Осуществляют окончательную вакуумную термическую обработку трубных изделий с последующими финишными отделочными операциями. В результате обеспечивают высокую стойкость к коррозии и формоизменению трубных изделий. 9 з.п. ф-лы, 1 табл., 1 пр.

Способ изготовления тройников

Изобретение относится к изготовлению тройников трубопроводов. Осуществляют нагрев листовой заготовки прямоугольной формы до температуры не ниже 700°С, формирование цилиндрической обечайки путем гибки заготовки, выполнение продольного сварного соединения, нагрев цилиндрической заготовки до температуры 500÷750°С, овализацию цилиндрической заготовки и ее нагрев до температуры 900÷1000°С. Затем осуществляют дифференцированное ступенчатое охлаждение части поверхности заготовки со сварным соединением, поперечный обжим заготовки с предварительным формированием ответвления без нарушения сплошности поверхности заготовки. Осуществляют выполнение отверстия в предварительно сформированном ответвлении, повторный нагрев заготовки до температуры 900÷1000°С и окончательный поперечный обжим заготовки с одновременной отбортовкой ответвления пуансоном. В результате повышается качество тройников. 2 з.п. ф-лы, 4 ил.

СТАЛЬНОЙ МАТЕРИАЛ И СТАЛЬНАЯ ТРУБА ДЛЯ НЕФТЯНЫХ СКВАЖИН

Изобретение относится к области металлургии, а именно к стальному материалу, используемому для изготовления стальных труб для нефтяных скважин. Материал содержит, мас.%: C: 0,15-0,45, Si: 0,10-1,0, Mn: 0,10 - менее чем 0,90, P: 0,05 или менее, S: 0,01 или менее, Al: 0,01-0,1, N: 0,010 или менее, Cr: 0,1-2,5, Mo: 0,35-3,0, Co: 0,50-3,0, Cu: 0-0,5, Ni: 0-0,5, Ti: 0-0,03, Nb: 0-0,15, V: 0-0,5, B: 0-0,003, Ca: 0-0,004, Mg: 0-0,004, Zr: 0-0,004, редкоземельный металл: 0-0,004, остальное - Fe и примеси. Микроструктура содержит в объемном отношении 90% или более отпущенного мартенсита, а состав удовлетворяет выражениям: C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15-Co/6+α ≥ 0,50, (3C+Mo+3Co)/(3Mn+Cr)≥1,0 и эффективный B=B-11(N-Ti/3,4)/14, где α составляет 0,250 при эффективном B, составляющем 0,0003% или более, и равен 0 при эффективном B, составляющем менее чем 0,0003%. Материал обладает превосходной стойкостью к SSC даже в среде с высоким давлением HS. 2 н. и 15 з.п. ф-лы, 3 ил., 2 табл.

ГОРЯЧЕКАТАНЫЙ СТАЛЬНОЙ ЛИСТ ДЛЯ ТОЛСТОСТЕННОГО ВЫСОКОПРОЧНОГО МАГИСТРАЛЬНОГО ТРУБОПРОВОДА, СВАРНЫЕ СТАЛЬНЫЕ ТРУБЫ ДЛЯ ТОЛСТОСТЕННОГО ВЫСОКОПРОЧНОГО МАГИСТРАЛЬНОГО ТРУБОПРОВОДА И СПОСОБ ИЗГОТОВЛЕНИЯ СВАРНОЙ СТАЛЬНОЙ ТРУБЫ

Изобретение относится к области металлургии. Предложен горячекатаный стальной лист для толстостенного высокопрочного магистрального трубопровода, имеющий высокий класс прочности API X60 - X80, предел текучести YS выше 415 МПа, предел прочности при растяжении TS выше 520 МПа и стойкость к хрупкому разрушению. Предложены сварная стальная труба, выполненная из горячекатаного стального листа, и способ изготовления сварной стальной трубы. Для достижения технического результата горячекатаный стальной лист имеет химический состав в мас.%: С 0,02 - 0,20, Mn 0,80 - 2,10, Si 0,01 - 0,50, P: 0,034 или менее, S 0,0050 или менее, Nb 0,01 - 0,15, Ti 0,001 - 0,030 и Al 0,001 - 0,080, остальное Fe и побочные примеси, при этом лист имеет микроструктуру, в которой основной фазой является структура превращения при непрерывном охлаждении (Zw) и в которой зерно в {001}плоскости, нормальное направление которой представляет собой направление ширины листа, составляет долю площади 10% или менее и имеет общий размер ...

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 ...

СПОСОБ ПОЛУЧЕНИЯ ТОЛСТОЛИСТОВОЙ СТАЛИ И СТАЛЬНЫХ ТРУБ ДЛЯ УЛЬТРАВЫСОКОПРОЧНОГО ТРУБОПРОВОДА

Изобретение относится к области металлургии. Для обеспечения предела прочности на разрыв 625 МПа и выше и отличной низкотемпературной ударной вязкости толстолистовую сталь для ультравысокопрочных трубопроводов получают из стали, содержащей, мас.%: С 0,03-0,08, Si 0,01-0,50, Mn 1,5-2,5, P 0,01 или меньше, S 0,0030 или меньше, Nb 0,0001-0,20, Al 0,0001-0,03, Ti 0,003-0,030, N 0,0010-0,0050, O 0,0050 или меньше, остальное Fe и неизбежные примеси, осуществляют разливку расплавленной стали в сляб, горячую прокатку сляба для получения толстолистовой стали и охлаждение поверхности толстолистовой стали при расходе воды 0,6 м3/(м2·мин) или меньше до достижения заданной температуры поверхности толстолистовой стали выше 540°С и охлаждение поверхности толстолистовой стали при расходе воды 1,3 м3/(м2·мин) или более. Из листа с помощью UO-пресса формуют трубу, проводят дуговую сварку под флюсом примыкающих участков листа с наружной и внутренней поверхностей, используя сварочную проволоку и агломерированный ...

СПОСОБ ПОЛУЧЕНИЯ ТОЛСТОЛИСТОВОЙ СТАЛИ И СТАЛЬНЫХ ТРУБ ДЛЯ УЛЬТРАВЫСОКОПРОЧНОГО ТРУБОПРОВОДА

Изобретение относится к области металлургии. Для обеспечения предела прочности на разрыв 915 МПа и выше и отличной низкотемпературной ударной вязкости выплавляют сталь, содержащую, мас.%: С 0,03-0,06, Si 0,01-0,50, Mn 1,5-2,5, P 0,01 или меньше, S 0,0030 или меньше, Nb 0,0001-0,20, Al 0,0005-0,03, Ti 0,003-0,030, В 0,0003-0,0030, N 0,0010-0,0050, О 0,0050 или меньше, остальное Fe и неизбежные примеси, осуществляют разливку расплавленной стали в сляб, горячую прокатку сляба для получения толстолистовой стали и водяное охлаждение, которое проводят до достижения поверхностью заданной температуры выше температуры начала мартенситного превращении точки MS, а затем охлаждение поверхности толстолистовой стали ведут путем повторения обработки, в которой утилизацию тепла проводят один или более раз и окончательно охлаждают поверхность толстолистовой стали до температуры точки MS или ниже. Из листа с помощью UO-пресса формуют трубу, проводят дуговую сварку под флюсом примыкающих участков листа с ...

СТАЛЬНОЙ МАТЕРИАЛ И СПОСОБ ПРОИЗВОДСТВА СТАЛЬНОГО МАТЕРИАЛА

Изобретение относится к области металлургии, а именно к стальному материалу, используемому в нефтяных и газовых скважинах. Материал имеет следующий химический состав в мас.%: C: более чем 0,50 до 0,80, Si: от 0,05 до 1,00, Mn: от 0,05 до 1,00, P: 0,025 или менее, S: 0,0100 или менее, Al: от 0,005 до 0,100, Cr: от 0,20 до 1,50, Mo: от 0,25 до 1,50, Ti: от 0,002 до 0,050, B: от 0,0001 до 0,0050, N: от 0,002 до 0,010, O: 0,0100 или менее, V: от 0 до 0,30, Nb: от 0 до 0,100, Ca: от 0 до 0,0100, Mg: от 0 до 0,0100, Zr: от 0 до 0,0100, Co: от 0 до 0,50, W: от 0 до 0,50, Ni: от 0 до 0,50, Cu: от 0 до 0,50, остальное - железо и примеси, причем количество растворенного C находится в диапазоне 0,010-0,060 мас.%. Материал имеет предел текучести в диапазоне 965-1069 МПа, отношение предела текучести к пределу прочности 90% или более, а также превосходную стойкость к сульфидному растрескиванию под напряжением. 2 н. и 16 з.п. ф-лы, 2 ил., 3 табл.

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 ГОРЯЧЕКАТАННОЙ СТАЛЬНОЙ ЛЕНТЫ И СТАЛЬНАЯ ЛЕНТА

... 1. Способ изготовления стальной ленты листового горячего проката толщиной 2-12 мм из стали, имеющей следующий химический состав содержащей, вес.%:остальное составляет железо и неустранимые примеси, отличающийся тем, что включает- аустенитное легирование стальной заготовки при температуре 1200-1350°С;- горячую прокатку стальной заготовки на пред-прокатной стадии;- прокатку стальной заготовки на листовом прокатном стане, причем температура 760-960°С достигается на последнем проходе; и- прямую закалку стальной ленты после последнего прохода на листовом прокатном стане, путем одноступенчатого охлаждения с градиентом 30-150°С/с до максимальной температуры 300°С, причем прямая закалка происходит в течение 15с в после последнего прохода.2. Способ по п.1, отличающийся тем, что конечная температура прямой закалки составляет максимально 100°С.3. Способ по п.1 или 2, отличающийся тем, что после прямой закалки стальную ленту используют для изготовления трубчатого изделия.4. Горячекатаная стальная лента ...

ВЫСОКОПРОЧНАЯ НЕРЖАВЕЮЩАЯ СТАЛЬ ДЛЯ НЕФТЯНЫХ СКВАЖИН И ТРУБА ИЗ ВЫСОКОПРОЧНОЙ НЕРЖАВЕЮЩЕЙ СТАЛИ ДЛЯ НЕФТЯНЫХ СКВАЖИН

... 1. Высокопрочная нержавеющая сталь для нефтяных скважин, обладающая высокой обрабатываемостью и имеющая химический состав, содержащий, в процентах по массе, С: максимум 0,05%, Si: максимум 1,0%, Mn: максимум 0,3%, P: максимум 0,05%, S: менее 0,002%, Cr: более 16% и максимум 18%, Мо: от 1,5 до 3,0%, Cu: от 1,0 до 3,5%, Ni: от 3,5 до 6,5%, Al: от 0,001 до 0,1%, N: максимум 0,025%, и О: максимум 0,01%, при этом баланс составляет Fe и примеси, причем микроструктура включает мартенситную фазу, от 10 до 48,5 об. % ферритной фазы, и максимум 10% об. фазы остаточного аустенита; причем сталь имеет предел текучести, равный по меньшей мере 758 МПа, и равномерное удлинение, равное по меньшей мере 10%.2. Нержавеющая сталь по п.1, при этом нержавеющая сталь включает, вместо части Fe, по меньшей мере один элемент, выбранный из группы, состоящей из V: максимум 0,30%, Nb: максимум 0,30%, Ti: максимум 0,30%, и Zr: максимум 0,30%.3. Нержавеющая сталь по п.1, при этом нержавеющая сталь включает, вместо части ...

ТРУБЫ ИЗ СПЛАВА НА ОСНОВЕ НИКЕЛЯ И СПОСОБ ИХ ПРИЗВОДСТВА

Способ изготовления труб для добычи нефти и газа

Изобретение относится к черной металлургии. Цель изобретения - повышение стойкости к сероводородному оаствескиванию. Из стали, содержащей, С 0,20-0,35%; Мп 0,35-0,9%; СгР,8-1,5% Мо 0,15-0,75%; не более 0,25% Ni; не более 0,35% С; не более 0,35% Si; не более 0,04% S; не более 0,04% Р; остальное железо, подвергнутой двойному электропшаковому переплаву, получают непрерывно-литую заготовку. Заготовки экструдируют до получения гильз с толщиной стенки 18,08 мм. Гильзы нагревают до 802 С с вьщерж- кой (в межкритический интервал температур ) и охлаждают до температуры завершения фазового превращения. Затем гильзы шлифуют по наружному диаметру , подвергают холодной прокатке на оправке до получения готовой трубы диаметром 177,8 мм и толщиной стенки 15,88 мм. Поперечное сечение гильзы превьш1ает поперечное сечение готовой трубы приблизительно на 20%. Готовые трубы подвергают термической обработке из межкристаллического интервала температур по описанному режиму, а затем закалке путем аустенизации в ...

Quenching tempering large thin-walled tubes - in straightening rolling mill stands between cooling nozzles

Thin-walled steel tubes of large diameters are quenched and tempered by passing them through a straightening rolling mill stand during their quenching down to a temperature of 400 to 600 degrees C. Both the inlet and the exit side of the mill stand is fitted with cooling nozzles. Another straightening rolling mill stand can follow to ensure the final contours. Thin-walled steel tubes with a dia. of 38 - 152 cm and a wall thickness of 6 - 38 mm can be produced with very accurate dimensions. The tubes have a higher strength and a better low-temp. toughness without the necessity of expensive alloys.

Metallbehälter mit evakuierter Doppelwand und dessen Herstellungsverfahren

THEROMECHANISCHE BEHANDLUNG VON METALLISCHE WERKSTOFFE

Hardened tubular hollow workpiece producing method, involves expanding workpiece by introducing fluid medium in finished forging, and quenching workpiece in forming tool during expansion by fluid medium

The method involves heating a tubular hollow workpiece (4) at high temperature of about 850 to 950 degree centigrade in an initial condition, and introducing the workpiece into a forming tool (2). The workpiece is expanded by introducing a fluid medium e.g. water emulsion, in a finished forging, and the workpiece is quenched in the forming tool during the expansion. The forming tool is cooled up to the withdrawal of the finished workpiece, after the introduction of the workpiece into the forming tool, where the workpiece is simultaneously expanded and quenched by the fluid medium.

Steel tubes with large dia. prodn. - by descaling, progressive local heating and quenching and widening

Steel tubes with large dia. are produced by (a) descaling the tube, pref. by >90%, (b) a heat-treatment comprising a progressive local heating of the steel tube from one end to the other in axial direction and quick cooling, and (c) widening the tube, e.g. by mechanical or hydraulic means. Tubes can be used as pipelines for natural gas and petroleum. Tubes have high accuracy of shape, tenacity and tensile stress. Heat-treatment comprises the quick and local heating of the tube to a temp. between the Ar3-transformation point and the temp. at which coarsening of the austenite grains sets in, and strong cooling to quench the tube.

PROCESS FOR THE MANUFACTURE OF RODS AND TUBES FROM STEELS WITH GREAT MECHANICAL PROPERTIES

VERFAHREN UND EINRICHTUNG ZUM HERSTELLEN NAHTLOSER STAHLROHRE

Flow Forming method

Inwardly coated tube

To manufacture tubes having a wear-resistant inside coating, such as gun barrels, hard material layers are deposited on the barrel and the layers are strain-hardened in their surface area by at least the ratio of the area by which the surface area is reduced by compression divided by the surface area of 0.001 ( DELTA F/F=1.10-3) or reducing the area of the layer by 0.1%.

HIGH QUALITY SEAMLESS STEEL PIPES

VERFAHREN ZUM HERSTELLEN VON NAHTLOSEN STAHLROHREN, INSBESONDERE FUER DIE ERDOELINDUSTRIE

STEEL TUBE FOR CAMP ELEMENTS AND PROCEDURE FOR ITS PRODUCTION AND CUTS

PROCEDURE FOR CONTINUOUS PULLING OF METAL TUBES.

USE OF A STEEL IN SCHWEFELWASSERSTOFFHALTIGER ATMOSPHERE.

METHOD FOR WORKING A WORKPIECE FOR A FUEL HIGH-PRESSURE ACCUMULATOR AND WORKPIECE FOR USING THIS METHOD

HIGH STRENGTH SEAMLESS STEEL PIPE EXCELLENT IN HYDROGEN-INDUCED CRACKING RESISTANCE AND ITS PRODUCTION METHOD

High strength steel pipes with excellent toughness at low temperature and sulfide stress corrosion cracking resistance

Embodiments of the present disclosure comprise carbon steels and methods of manufacturing pipes having a wall thickness greater than or equal to about 8 mm and less than or equal to about 35 mm there from. In one embodiment, a steel composition is provided that yields an average austenite grain size greater than about 15 tm. Based upon this composition, a quenching sequence has been determined that provides a microstructure of greater than or equal to about 60% by volume, and less than or equal to about 40% by volume lower bainite, without substantial formation of ferrite, upper bainite, or granular bainite. After quenching, the pipe may be subjected to tempering. The yield strength of the quenched and tempered pipes may be greater than about 550 MPa (80 ksi) or 625 MPa (90 ksi) and mechanical property measurements find the quenched and tempered pipes suitable for 550 MPa (80 ksi) grade and 625 MPa (90 ksi) grade. 102 Steel Making 104 Hot Forming 106A Austenizing 106B Quenching 106C Tempering ...

Martensitic stainless steel pipe for oil well

Seamless steel pipe for line pipe, and method for producing same

Provided is a seamless steel pipe for a line pipe, the seamless steel pipe having a chemical composition which contains, in terms of mass %, 0.03-0.10% of C, 0.50% of Si, 1.0-2.0% of Mn, 0.050% of P, 0.005% of S, 0.05-1.0% of Cr, 0.01-0.30% of Mo, 0.001-0.10% of Al, 0.01% of N, 0.04-2.0% of Ni, 0.0005-0.0050% of Ca, 0-2.0% of Cu, 0-0.05% of Ti, 0-0.05% of Nb and 0-0.10% of V, with the remainder consisting of Fe and impurities, and which satisfies the conditions Cu+Ni: 0.10% and Mo+V: 0.30%, wherein metal particles having an average circle-equivalent diameter of 0.1-5 m and consisting mainly of Ni or Cu are present in scale formed on the surface of the steel pipe, and the distance from the boundary between the base material of the steel pipe and the scale to a region in which the metal particles are not present is 20 m or higher.

Seamless steel pipe and method for producing the same

Provided is a seamless steel pipe having high strength and toughness even with thick walls. This seamless steel pipe contains C in an amount of 0.03 to 0.08%, Si in an amount of 0.25% or less, Mn in an amount of 0.3 to 2.0%, P in an amount of 0.05% or less, S in an amount of 0.005% or less, Al in an amount of 0.001 to 0.10%, Cr in an amount of 0.02 to 1.0%, Ni in an amount of 0.02 to 1.0%, Mo in an amount of 0.02 to 0.8%, N in an amount of 0.002 to 0.008%, Ca in an amount of 0.0005 to 0.005%, and Nb in an amount of 0.01 to 0.1% (amounts given in percent by mass), the remainder comprising Fe and impurities, and the wall thickness being 50 mm or more. In a cross section orthogonal to the axial direction of the seamless steel pipe, the average crystal grain size of old austenite grains is less than 80 ...

High-frequency straight welded pipe and manufacturing method thereof

The present invention discloses a high-frequency straight welded pipe. The high-frequency straight welded pipe comprises the following chemical element percentages by mass: 0.042-0.056% of C, 0.18-0.22% of Si, 0.75-0.95% of Mn, 0.0064-0.015% of P, 0.0006-0.002% of S, 0.012-0.018% of Ti, 0.001-0.002% of V, 0.026-0.038% of Al, 0.080-0.13% of Ni, 0.020-0.029% of Nb, 0.125-0.135% of Cu, 0.018-0.03% of Cr, 0.004-0.008% of Mo, 0-0.0005% of B, 0.001-0.003% of Ca, and the balance of Fe and other inevitable impurities. Meanwhile, further disclosed is a manufacturing method for the high-frequency straight welded pipe.

Low-alloy steel pipe for oil well

Provided is a low-alloy steel pipe for an oil well, which has a yield strength of 827MPa or more, and excellent SCC resistance. This low-alloy steel pipe for an oil well includes, in mass%, C: over 0.35 and up to 0.65%, Si: 0.05-0.50%, Mn: 0.10-1.00%, Cr: 0.40-1.50%, Mo: 0.50-2.00%, V: 0.05-0.25%, Nb: 0.01-0.04%, sol. Al: 0.005-0.10%, N: 0.007% or less, Ti: 0-0.012%, and Ca: 0-0.005%. The remainder comprises Fe and impurities, the impurities comprising P: 0.020% or less, S: 0.002% or less, O: 0.006% or less, Ni: 0.10% or less, Cu: 0.03% or less, and B: 0.0005% or less. In this structure, the number of cementites that have a circle equivalent diameter of 200nm or more is 200/100μm ...

STEEL PIPE FOR AN AIRBAG SYSTEM AND A METHOD FOR ITS MANUFACTURE

L'invention concerne un tube d'acier haute résistance destiné à un système de coussin de sécurité gonflable qui comprend une composition chimique en pourcentage en poids selon laquelle les éléments suivants sont compris entre les valeurs suivantes: C: entre 0,05 et 0,20 %, Si: entre 0,1et 1,0 %, P: 0,025 % ou moins, S: 0,010 % ou moins, Cr: entre 0,05 et 1,0 %, Al: 0,10 % ou moins, Ti et/ou Mn: une ou des quantités satisfaisant aux conditions (1) Ti = 0,02 % et (2) 0,4 = Mn + 40 X Ti = 1,2; et en complément: Fe. La composition d'acier de l'invention peut contenir en outre (i) un ou plusieurs des éléments suivants: Mo: entre 0,05 et 0,50 %, Ni: entre 0,05 et 1,5 %, V: entre 0,01 et 0,2 %; et B: entre 0,0003 et 0,005 %; (ii) un ou plusieurs des éléments suivants: Cu: entre 0,05 et 0,5 %; et Nb: entre 0,003 et 0,1 %; et/ou (iii) un ou plusieurs des éléments suivants: Ca: entre 0,0003 et 0,01 %, Mg: entre 0,0003 et 0,01 %; et REM: entre 0,0003 et 0,01 %. L'invention concerne également un procédé ...

COMBINED MECHANICAL AND THERMAL PROCESSING METHOD FOR PRODUCTION OF SEAMLESS STEEL PIPE

HIGH-STRENGTH STEEL EXCELLENT IN LOW TEMPERATURE TOUGHNESS AND TOUGHNESS AT WELD HEAT-AFFECTED ZONE, METHOD FOR PRODUCING THE SAME, AND METHOD FOR PRODUCING HIGH-STRENGTH STEEL PIPE

The present invention provides an ultra-high- strength steel pipe excellent in weldability on site and a method for producing the steel pipe by improving the reliability of the low temperature toughness of a steel to which elements to enhance hardenability are added for furthering high-strengthening and also improving toughness at a weld heat affected zone subjected to double or more layer welding and, in the method, the steel is made to consist of a structure composed of bainite and/or martensite by containing prescribed amounts of C, Si, Mn, P, S, Ni, Mo, Nb, Ti, Al and N, and, as occasion demands, one or more of B, V, Cu, Cr, Ca, REM and Mg, and regulating C, Si, Mn, Cr, Ni, Cu, V and Mo, those being elements to enhance hardenability, by a specific relational expression. The diameter of prior austenite grains may be regulated in a prescribed range. The method includes the steps of heating a casting to a temperature not lower than the Ac3 point, hot rolling it, and thereafter cooling ...

PROCESS FOR PRODUCING BEND PIPE FOR LINE PIPE AND BEND PIPE FOR LINE PIPE

A steel pipe is provided, which comprises, by mass, 0.009% or less C, 1.0 % or less Mn, 1.0% or less Si, 0.04% or less P, 0.005% or less S, 0.01 to 0. 2% Ti, 0.01 to 0.10% V, 0.001 to 0.1% Al, 0.1% or less N, 4.0 to 8.0% Ni, 9. 0 to 15.0% Cr, 1.5 to 7.0% Mo and the balance Fe and impurities. The provide d steel pipe is bending worked into a bend pipe. The bend pipe is quenched a t a temperature of below 950°C. The quenched bent pipe is tempered. Accordin gly, the obtained bend pipe has excellent resistance to SSC.

HIGH STRENGTH STEEL PIPES WITH EXCELLENT TOUGHNESS AT LOW TEMPERATURE AND SULFIDE STRESS CORROSION CRACKING RESISTANCE

Embodiments of the present disclosure comprise carbon steels and methods of manufacturing pipes having a wall thickness greater than or equal to about 8 mm and less than or equal to about 35 mm there from. In one embodiment, a steel composition is provided that yields an average austenite grain size greater than about 15 µm. Based upon this composition, a quenching sequence has been determined that provides a microstructure of greater than or equal to about 60% by volume, and less than or equal to about 40% by volume lower bainite, without substantial formation of ferrite, upper bainite, or granular bainite. After quenching, the pipe may be subjected to tempering. The yield strength of the quenched and tempered pipes may be greater than about 550 MPa (80 ksi) or 625 MPa (90 ksi) and mechanical property measurements find the quenched and tempered pipes suitable for 550 MPa (80 ksi) grade and 625 MPa (90 ksi) grade.

SEAMLESS STEEL PIPE FOR STEAM INJECTION, AND METHOD FOR MANUFACTURING THE SAME

Disclosed is a steel pipe for steam injection, which exhibits high yield stress even at a temperature of 350°C. Specifically disclosed is a seamless steel pipe for steam injection which has a chemical composition that includes, in terms of mass%, 0.03-0.08% C, 0.05-0.5% Si, 1.5-3.0% Mn, more than 0.4 but at most 1.2% Mo, 0.005-0.100% Al, 0.001-0.005% Ca, 0.002-0.015% N, at most 0.03% P, at most 0.01% S and at most 1.5% Cu, with the remainder being Fe and impurities. The seamless steel pipe for steam injection is manufactured via a hot working process, followed by a water cooling process, a quenching process and a tempering process.

METHOD OF MANUFACTURING HIGH PRESSURE FUEL INJECTION PIPE MATERIALS

Title of the Invention: Method of Manufacturing High Pressure Fuel Injection Pipe Materials This invention is made with a view to remarkably improving the smoothness of the inside surface of the hole of a high pressure fuel injection pipe to be used for Diesel internal combustion engines and to improving the true circularity of the hole shape and the uniformity of the hole diameter and is a method of manufacturing high pressure fuel injection pipe materials characterized by forming a pipe body by cutting and removing an interposed slag layer collected and deposited near the center of a steel bar material in the steel bar direction and then gradually elongating the pipe body to be of desired dimensions by the repetition of an annealing treatment in a non-oxidizing or reducing atmosphere and a drawing and reducing treatment by using both die and plug. - 1 ...

MANUFACTURE OF ELECTRICALLY WELDED STEEL PIPE

D-16958 - RSD 78.41 For skelp to make pipe having a seam butt-joined as by electrical resistance or submerged arc welding, skelp is made by pouring a base melt of rimming steel into an ingot mold to about 80 to 95% full and then after a shell of rimmed steel has solidified against the mold wall, completing pouring of the same melt while adding further material to the molten core, e.g. more C or Mn, and Al or the like for killing, so that the solidified ingot has a core of desired high strength, killed or semi-killed steel. The ingot is processed to desired skelp by hot rolling, the top and bottom regions being suitably cropped, so that the skelp has a main body of the high strength steel, bordered lengthwise by integral edge zones, e.g. 1/2 inch or more wide, of the rimmed steel, free of unwanted inclusions. When rolled to pipe shape, with finished edges, the edge zones are electrically butt welded, such operation being effected with unusual facility. In the completed pipe, the weld region ...

AS-PIERCED TUBULAR PRODUCTS

As-pierced steel casing is made by heating a killed steel consisting of 0.20-0.35 carbon, 1.0-2.0 manganese, up to about 0.60 silicon, up to about 0.04 each of phosphorous and sulfur, 0.05-0.25 vanadium, from 0.005-0.025 nitrogen and/or from 0.0100.10 columbium, and the balance iron, to a temperature of at least about 2200.degree.F to dissolve vanadium carbides, piercing the steel, and allowing said steel to cool to effect precipitation of vanadium carbides with resulting refinement of austenite to a grain size of about ASTM 5 or finer and of ferrite to a grain size of about ASTM 7 or finer. The resulting pierced steel has a yield strength of 80-110 ksi, a minimum ultimate tensil strength of 100 ksi, a minimum elongation of 12-1/2% in two inches, and a ferrite-pearlite microstructure having a ferrite grain size of about ASTM 7 or finer.

METHOD FOR PRODUCING LARGE DIAMETER STEEL PIPES

HIGH TENSION STEEL PLATE, WELDED STEEL PIPE AND METHOD FOR PRODUCTION THEREOF

A high tension steel plate, which has a content of carbon equivalent Pcm represented by the following formula (1) of 0.180 to 0.220 % and a surface hardness of 285 or less in terms of Vickers, and has a structure wherein the percentage of a martensite austenite constituent in a surface layer portion is 10 % or less, the percentage of a mixed structure of ferrite and bainite in a portion inside the surface layer portion is 90 % or more and the percentage of bainite in the mixed structure is 10 % or more, a lath of bainite has a thickness of 1 .mu.m or less and a length of 20 .mu.m or less, and the segregation level, which is the ratio of an Mn concentration in the central segregated portion to an Mn concentration in a part having a depth from the surface of 1/4 of the thickness of the plate, is 1.3 or less. Pcm = C + Si/30 + (Mn + Cu + Cr)/20 + Ni/60 + Mo/15 + V/10 + 5B (1) wherein each symbol in the formula (1) represents the mass % of each element. The high tension steel plate has a yield ...

AS-ROLLED TYPE K55 ELECTRIC RESISTANCE WELDED OIL WELL PIPE AND HOT-ROLLED STEEL SHEET

An As-rolled type K55 electric-resistance-welded oil well pipe which comprises, in terms of mass%, 0.30-0.50% C, 0.05-0.40% Si, 0.50-1.20% Mn, 0-0.030% P, 0-0.020% S, 0.002-0.080% Al, 0-0.0080% N, 0-0.30% Cu, 0-0.30% Ni, 0-0.30% Cr, 0-0.10% Mo, 0-0.10% V, 0-0.050% Nb, 0-0.030% Ti, 0-0.0100% Ca, and Fe and impurities as the remainder. In an L cross-section of the base material located at a position of 90º, the metallographic structure at a depth of 1/4 the wall thickness is a ferrite/pearlite structure including flattened prior ? grains, includes grain-boundary ferrite and intragranular ferrite, and has a total areal proportion of the grain-boundary ferrite and intragranular ferrite of 10-30%.

SEAMLESS STEEL PIPE AND METHOD OF MANUFACTURING THE SAME

A seamless steel pipe is provided that provides a yield strength of 555 MPa or higher and good SSC resistance in a reliable manner. A seamless steel pipe contains, in mass %, C: 0.02 to 0.15 %; Si: 0.05 to 0.5 %; Mn: 0.30 to 2.5 %; Al: 0.01 to 0.10 %; Ti: 0.001 to 0.010 %; N: up to 0.007 %; Cr: 0.05 to 1.0 %; Mo: not less than 0.02 % and less than 0.5 %; Ni: 0.03 to 1.0 %; Cu: 0.02 to 1.0 %; V: 0.020 to 0.20 %; Ca: 0.0005 to 0.005 %; and Nb: 0 to 0.05 %, among others, where the carbon equivalent Ceq is not less than 0.430 % and less than 0.500 %, the main phase of the microstructure from the surface layer to an in-the-wall portion is tempered martensite or tempered bainite, the size of prior austenite grains is lower than 6.0 in crystal grain size number according to ASTM E112-10, a portion between a position at 1 mm from the inner surface and a position at 1 mm from the outer surface has a Vickers hardness of 250 Hv or lower, and the yield strength is 555 MPa or higher.

SEAMLESS STEEL PIPE AND METHOD FOR PRODUCING SAME

A seamless steel pipe which has a chemical composition that contains, in mass%, 0.10-0.20% of C, 0.05-1.0% of Si, 0.05-1.2% of Mn, 0.025% or less of P, 0.005% or less of S, 0.20% or less of Cu, 0.007% or less of N, 0.20-0.50% of Ni, 0.30% or more but less than 0.50% of Cr, 0.30-0.50% of Mo, 0.01-0.05% of Nb, 0.001-0.10% of Al, 0.0005-0.0020% of B, 0.003-0.050% of Ti, 0.01-0.20% of V and 0-0.025% in total of one or more elements selected from among Ca, Mg and REM, with the balance made up of Fe and unavoidable impurities, and wherein: Pcm = (C + (Si/30) + (Mn/20) + (Cu/20) + (Ni/60) + (Cr/20) + (Mo/15) + (V/10) + 5B) = 0.30; the tempered martensite in the metal structure is 90% by area or more; the tensile strength is 980 MPa or more; and the Charpy impact value at -40°C as determined using a 2 mm V-notch test piece is 75 J/cm2 or more.

STEEL PIPE FOR AIR BAG INFLATOR AND METHOD FOR PRODUCTION THEREOF

STEEL PRODUCT FOR STRUCTURAL MEMBER OF AUTOMOBILE AND METHOD FOR PRODUCTION THEREOF

A method for producing a steel product which comprises providing a steel slab having a chemical composition satisfying C: 0.18 to 0.29 %, Si: 0.06 to 0.45 %, Mn: 0.91 to 1.85 %, P: 0.019 % or less, S: 0.0029% or less, sol.Al: 0.015 to 0.075%, N: 0.0049 % or less, O: 0.0049 % or less, B: 0.0001 to 0.0029 %, Nb: 0.001 to 0.019 %, Ti: 0.001 to 0.029 %, Cr: 0.001 to 0.195 %, Mo: 0.001 to 0.195 %, and 0.4 or more and less than 0.58 of Ceq, and satisfying that the sum (.chi.) of hardenability multiples according to Grossmann being aware of B is 1.2 or more and less than 1.7, heating the steel slab to 1160 to 1320~C, subjecting the resultant slab to a hot finish rolling having an ending temperature for the finish rolling of 750 to 980~C, annealing the rolled product for a period of 2s or more before winding, and then winding the product up at a temperature of 560 to 740~C, to thereby produce a hot-rolled steel belt which has a structure having an average grain diameter (df) corresponding to a ...

ELECTRIC RESISTANCE WELDED STEEL TUBE FOR COILED TUBING AND METHOD FOR MANUFACTURING THE SAME

Provided are: an electric resistance welded steel tube for coiled tubing which has a yield strength of 896 MPa or higher, and exhibits excellent low cycle fatigue resistance, without being subjected to whole tube quenching treatment and reheating tempering treatment after electric resistance welding; and a production method therefor. The present invention has a specific content, in mass%, of C, Si, Mn, P, S, Al, Cr, Cu, Ni, Mo, Nb, V, Ti, and N, and has a structure comprising, in volume fraction, 2-10% of retained austenite, and 20% or less of martensite, the remainder being bainite. The present invention has a yield strength of 896 MPa or higher, and a uniform elongation of 9.0% or higher.

A METHOD OF MANUFACTURING A HEAVY WALL SEAMLESS STEEL PIPE FOR LINE PIPE

A heavy wall seamless steel pipe for line pipe with a high strength and increased toughness, which has a chemical composition, by mass%, that consists of C: 0.03 to 0.08%, Si: not more than 0.25%, Mn:0.3 to 2.5%, Al: 0.001 to 0.10%, Cr: 0.02 to 1.0%, Ni: 0.02 to 1.0%, Mo: 0.02 to 1.2%, Ti:0.004 to 0.010%, N:0.002 to 0.008%, and 0.0002 to 0.005%, in total, of at least one selected from Ca, Mg and REM, and the balance Fe and impurities, optionally including V: 0 to 0.08%, Nb: 0 to 0.05% or Cu: 0 to 1.0%,and that P and S among impurities are not more than 0.05% and not more than 0.005% respectively. It may contain 0.0003 to 0.01% of boron. A manufacturing method thereof is characterized by cooling rate, heating condition for piercing, and heat treating after pipe making.

STEEL STRUCTURE FOR HYDROGEN GAS, METHOD FOR PRODUCING HYDROGEN STORAGE TANK, AND METHOD FOR PRODUCING HYDROGEN LINE PIPE

Provided is a steel structure for hydrogen, such as a pressure accumulator for hydrogen or a line pipe for hydrogen, which has a reduced fatigue crack growth rate, and superior hydrogen embrittlement resistance in a high-pressure hydrogen environment compared to conventional steel. The steel structure for hydrogen, which has excellent hydrogen embrittlement resistance in high-pressure hydrogen gas, has a steel composition having either 10-95% bainite by surface area, 10-95% martensite by surface area, or 10-95% pearlite by surface area, with the remainder substantially comprising ferrite.

ELECTRIC RESISTANCE WELDED STEEL PIPE FOR HIGH-STRENGTH HOLLOW STABILIZER, METHOD FOR MANUFACTURING ELECTRIC RESISTANCE WELDED STEEL PIPE FOR HIGH-STRENGTH HOLLOW STABILIZER, HIGH-STRENGTH HOLLOW STABILIZER, AND METHOD FOR MANUFACTURING HIGH-STRENGTH HOLLOW STABILIZER

Provided are an electric resistance welded steel tube for a high-strength hollow stabilizer having excellent corrosion fatigue resistance characteristics, a method for manufacturing an electric resistance welded steel tube for a high-strength hollow stabilizer, a high-strength hollow stabilizer, and a method for manufacturing a high-strength hollow stabilizer. An electric resistance welded steel tube in which an electric resistance welded steel tube obtained by electric resistance welding a steel plate and forming a tube is further subjected to rolling reduction while hot, the electric resistance welded steel tube having a composition including, in terms of mass%, 0.20-0.40% C, 0.1-1.0% Si, 0.1-2.0% Mn, 0.01-0.10% Al, 0.01-0.5% Cr, 0.01-0.05% Ti, 0.0005-0.005% B, 0.0001-0.0050% Ca, and 0.0050% or less of N, the remainder comprising Fe and unavoidable impurities, and a metallographic structure in which TiS particles having a particle diameter of 10 µm or greater and MnS particles having ...

ELECTRIC RESISTANCE WELDED STEEL PIPE FOR HIGH-STRENGTH HOLLOW STABILIZER, METHOD FOR MANUFACTURING ELECTRIC RESISTANCE WELDED STEEL PIPE FOR HIGH-STRENGTH HOLLOW STABILIZER, HIGH-STRENGTH HOLLOW STABILIZER, AND METHOD FOR MANUFACTURING HIGH-STRENGTH HOLLOW STABILIZER

Provided are an electric resistance welded steel tube for a high-strength hollow stabilizer having excellent corrosion fatigue resistance characteristics, a method for manufacturing an electric resistance welded steel tube for a high-strength hollow stabilizer, a high-strength hollow stabilizer, and a method for manufacturing a high-strength hollow stabilizer. An electric resistance welded steel tube in which an electric resistance welded steel tube obtained by electric resistance welding a steel plate and forming a tube is further subjected to rolling reduction while hot, the electric resistance welded steel tube having a composition including, in terms of mass%, 0.20-0.40% C, 0.1-1.0% Si, 0.1-2.0% Mn, 0.01-0.10% Al, 0.01-0.5% Cr, 0.01-0.05% Ti, 0.0005-0.005% B, 0.0001-0.0050% Ca, and 0.0050% or less of N, the remainder comprising Fe and unavoidable impurities, and a metallographic structure in which TiS particles having a particle diameter of 10 µm or greater and MnS particles having ...

HIGH PERFORMANCE MATERIAL FOR COILED TUBING APPLICATIONS AND THE METHOD OF PRODUCING THE SAME

Embodiments of the present disclosure are directed to coiled steel tubes and methods of manufacturing coiled steel tubes. In some embodiments, the final microstructures of the coiled steel tubes across all base metal regions, weld joints, and heat affected zones can be homogeneous. Further, the final microstructure of the coiled steel tube can be a mixture of tempered martensite and bainite.

CR-CONTAINING AUSTENITIC ALLOY TUBE AND METHOD FOR PRODUCING THE SAME

Provided is a Cr-containing austenite alloy pipe with a chrome oxide coating film that is 0.05-1.5 µm thick and has the relationship shown in formula (i) formed on an inside surface thereof, wherein the C average concentration within a depth of 5-10 µm from a surface layer part on the inside surface side of the pipe is less than the C concentration of the starting material. 0.4?d1/d2?2.5 (i), wherein d1 and d2 are the chrome oxide coating material thicknesses (µm) at each end of the pipe.

AUSTENITIC ALLOY TUBE

An austenitic alloy tube is one that has undergone a cold working treatment and an annealing/heating treatment, and has a metallic structure that contains, in mass%, 0.01 to 0.15% of C, 10.0 to 40.0% of Cr and 8.0 to 80.0% of Ni and fulfills formulae (i) to (iii). R = f1 (i) R = I220/I111 (ii) f1 = 0.28×(F111 8.0/(F111 8.0+0.358.0)) (iii) In the formulae, R represents the ratio of the integrated intensity of {220} on a surface layer to the integrated intensity of {111} on the surface layer wherein the integrated intensities are obtained by a grazing incidence X-ray diffraction method; I220 represents the above-mentioned integrated intensity of the {220}; I111 represents the above-mentioned integrated intensity of the {111}; and F111 represents the half width value of a diffraction peak for the {111} on the surface layer which is obtained by the grazing incidence X-ray diffraction method.

PROCESS FOR MANUFACTURING A STEEL TUBE FOR AIR BAGS

A process for producing a high-strength and high-toughness steel pipe for air bags is disclosed with which it is possible to simplify the step of cold drawing and reduce alloy cost. The process comprises: forming a seamless steel pipe from a steel which contains, in terms of mass%, 0.04-0.20% C, 0.10-0.50% Si, 0.10-1.00% Mn, up to 0.025% P, up to 0.005% S, up to 0.10% Al, 0.01-0.50% Cr, 0.01-0.50% Cu, and 0.01-0.50% Ni, with the remainder comprising Fe and incidental impurities; subjecting this seamless steel pipe to cold drawing at least once so as to result in a reduction of area exceeding 40%, thereby making the steel pipe have a given size; heating the drawn steel pipe to a temperature which is the Ac3 point or higher at a rate of 50 ºC/s or higher; subsequently cooling the heated steel pipe so that the cooling rate in the temperature range of at least 850-500ºC is 50 ºC/s or higher, thereby quench-hardening the steel pipe; and then tempering the steel pipe at a temperature which is ...

HIGH-FREQUENCY STRAIGHT WELDED PIPE AND MANUFACTURING METHOD THEREOF

The present invention discloses a high-frequency straight welded pipe. The high-frequency straight welded pipe comprises the following chemical element percentages by mass: 0.042-0.056% of C, 0.18-0.22% of Si, 0.75-0.95% of Mn, 0.0064-0.015% of P, 0.0006-0.002% of S, 0.012-0.018% of Ti, 0.001-0.002% of V, 0.026-0.038% of Al, 0.080-0.13% of Ni, 0.020-0.029% of Nb, 0.125-0.135% of Cu, 0.018-0.03% of Cr, 0.004-0.008% of Mo, 0-0.0005% of B, 0.001-0.003% of Ca, and the balance of Fe and other inevitable impurities. Meanwhile, further disclosed is a manufacturing method for the high-frequency straight welded pipe.

LOW ALLOY STEEL FOR OIL COUNTRY TUBULAR GOODS HAVING EXCELLENT SULFIDE STRESS CRACKING RESISTANCE AND MANUFACTURING METHOD THEREFOR

The low alloy steel for oil country tubular goods according to the present invention has a chemical composition containing, by mass percent, C: 0.56 to 1.00%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: at most 0.025%, S: at most 0.010%, Al: 0.005 to 0.100%, Mo: 0.40 to 1.00%, V: 0.05 to 0.30%, and O: at most 0.010%, the balance being Fe and impurities, wherein the yield stress thereof is at least 862 MPa, and the half-value width of a [211] crystal surface obtained by X-ray diffraction is at most 0.50°.

HIGH-DUCTILITY, HIGH-STRENGTH STEEL PRODUCT AND PROCESS FOR PRODUCTION THEREOF

A steel product having a structure composed mainly of ferrite or ferrite plus pearlite or ferrite plus cementite. A steel pipe produced from this steel product by rolling at a ferrite recrystallization temperature such that the reduction of area is greater than 20%. This steel pipe is characterized by grain size not greater than 3 .mu.m, preferably not greater than 1 .mu.m, elongation greater than 20%, tensile strength (TS : MPa) and elongation (El : %) whose product is greater than 10000, and percent ductile fracture greater than 95%, preferably 100%, measured by Charpy impact test on an actual pipe at -100.degree.C. The structure is characterized by C : 0.005-0.03%, Si : 0.01-3.0%, Mn : 0.01-2.0%, and Al : 0.001-0.10% on a weight basis, and is composed of ferrite or ferrite and a secondary phase, with ferrite grains being not greater than 3 .mu.m and the secondary phase having an areal ratio not more than 30%. The steel pipe is produced from a steel pipe stock having the above-mentioned ...

Verfahren zur Herstellung von Rohren aus austenitischem Stahl.

Procédé pour augmenter la résistance mécanique de corps creux en acier.

Procédé pour l'amélioration des propriétés physiques d'une pièce moulée cylindrique

Verfahren zur Herstellung eines feinkörnigen Baustahls

PIPE WITH AN INTERIOR COATING.

STEEL FOR TUBULAR PRODUCTS OIL FIELD ASSORTMENT AND METHOD OF ITS PRODUCTION

HIGH-STRENGTH STEEL MATERIAL FOR OIL WELL AND PIPE FOR OIL WELLS

METHOD OF PREPARING HIGH-LASTING STEEL MATERIAL WITH EXCELLENT RESISTANCE TO CRACKING UNDER STRESS AGAINST SULFIDE

СТАЛЬНАЯ ТРУБА С ВИСОКОЙ РОЗШИРЕННОСТЬЮ И СПОСОБ ЕЁ ИЗГОТОВЛЕНИЯ (ВАРИАНТЫ)

Стальная труба с высокой расширенностью, содержащая, масс. %: С: от 0,1 до 0,45 %; Si: от 0,3 до 3,5 %; Mn: от 0,5 до 5 %; Р: 0,03 % или менее; S: 0,01 % или менее; растворимый Al: от 0,01 до 0,8 % (0,1 % или более в том случае, если содержание Si составит менее, чем 1,5 %); N: 0,05 % или менее; О: 0,01 % или менее, с балансом из Fe и загрязняемых примесей, которая имеет прочность на растяжение, которая равна 600 МПа или более, и равномерное удлинение, которое удовлетворяет следующей формуле (1). Стальная труба, которая имеет вышеописанный химический состав, может быть получена, например, нагреванием до температуры, которая составляет от 700 до 790 °C, а затем принудительным охлаждением до температуры, которая составляет 100 °C или менее, со скоростью охлаждения, которое равно 100 °C/мин. или более, при температуре, которая составляет от 700 до 500 °C, в соответствии с выражением. u·el≥28-0,0075TS (1), где u-el равномерное удлинение (%), TS – прочность на растяжение (МПа).

STEEL FOR MANUFACTURING OF SEAMLESS STEEL PIPE FOR OIL WELLS AND/OR GASSER (VARIANTS) AND METHOD FOR MANUFACTURING OF SEAMLESS STEEL FROM THIS STEEL

METHOD FOR PRODUCING HIGH-STRENGTH STEEL MATERIAL HAVING EXCELLENT SULFIDE STRESS CRACKING RESISTANCE

STEEL FOR OIL WELL PIPE, AND METHOD FOR PRODUCING SAME

HIGH-STRENGTH STEEL MATERIAL FOR OIL WELL USE, AND OIL WELL PIPE

Ultra-high strength secondary hardening steels with excellent toughness and weldability and method thereof

表面具有下贝氏体组织的滚动轴承钢及其制备方法

... 本发明涉及一种从1C-1.5Cr型系列钢制备滚动轴承部件如滚动轴承圈的方法，以及由所述的方法所制得的滚动轴承部件。至少滚动轴承部件的表面具有贝氏体组织。业已发现，与未经冷轧处理的部件相比，所述组织的使用寿命明显增加。优选采用下贝氏体组织，该组织可从通常的、铁素体的1C-1.5Cr型钢制得。在奥氏体化处理之前，所述的钢进行冷变形处理。淬火，使之得到贝氏体组织。 ...

Tube cold rolling - raises workpiece temp which heat is utilized in final heat treatment

Manufactoring process of tubes rolled without welding, starting from mild steels of having undercutting of high-qualities of machining

MANUFACTORING PROCESS Of ONE PROFILES TUBULAR OUT OF STEEL INTENDS FOR the REINFORCEMENT DOORS FOR MOTOR VEHICLES

Manufactoring process of the steel casings in general

연료 분사관용 이음매 없는 강관

... 고강도이고, 우수한 내내압 피로 특성을 갖는 연료 분사관용 이음매 없는 강관을 제공한다. 특정의 조성과, 냉간 인발, 열처리를 행한 후의 구γ입경의 평균 입경이, 관축 방향 단면에서, 150㎛ 이하인 조직을 갖는다. 이것에 의하여, 피로 균열의 진전이 억제되어, 고분사압의 연료 분사관으로서 적합한, 인장 강도(TS): 500㎫ 이상이고, 내내압 피로 특성이 우수한 이음매 없는 강관으로 할 수 있다. 또한 상기한 조성에 더하여, 추가로 Cu, Ni, Cr, Mo, B 중으로부터 선택된 1종 또는 2종 이상, 및/또는, Ti, Nb, V 중으로부터 선택된 1종 또는 2종 이상, 및/또는, Ca를 함유해도 좋다.

THICK-WALLED ELECTRIC-RESISTANCE-WELDED STEEL PIPE AND PROCESS FOR PRODUCING SAME

STEEL TUBE FOR FUEL INJECTION TUBE AND PROCESS FOR PRODUCING THE SAME

HOT ROLLED STEEL SHEET FOR STEEL PIPE HAVING EXCELLENT LOW-TEMPERATURE TOUGHNESS AND STRENGTH AND METHOD FOR MANUFACTURING SAME

The present invention relates to a hot rolled steel sheet for a steel pipe used for construction, a line pipe, a marine structure, or the like, and a method for manufacturing the same. According to the present invention, a hot rolled steel sheet for a steel pipe having excellent low-temperature toughness and strength comprises: 0.03-0.12 wt% of C; 0.01-0.70 wt% of Si; 1.0-2.5 wt% of Mn; an amount equal to or less than 0.01 wt% of S; an amount equal to or less than 0.03 wt% of P; 0.01-0.13 wt% of Ti; 0.0005-0.011 wt% of N; 0.01-0.15 wt% of Nb; 0.1-0.6 wt% of Ni; 0.1-0.6 wt% of Mo; 0.01-0.6 wt% of Cr; 0.001-0.004 wt% of Ca; 0.01-0.1 wt% of V; and remainder consisting of Fe and inevitable impurities. COPYRIGHT KIPO 2016 ...

HOT-ROLLED STEEL SHEET WITH EXCELLENT WORKABILITY AND IMPACT TOUGHNESS FOR OIL WELL PIPE, HOT-ROLLED STEEL SHEET MANUFACTURING METHOD, AND HIGH STRENGTH STEEL PIPE MANUFACTURED BY HOT-ROLLED STEEL SHEET MANUFACTURING METHOD

The present invention provides a steel pipe, and a hot-rolled steel sheet for an oil well pipe having excellent workability, impact toughness, yield strength, and tensile strength without thermally treating the hot-rolled steel sheet after treatment of the hot-rolled steel sheet. The present invention comprises: 0.15-0.45 wt% of carbon (C), 0.1-0.5 wt% of silicon (Si), 0.1-1.0 wt% of manganese (Mn), 0.02 wt% or less of phosphorus (P) (excluding 0 wt%), 0.01 wt% or less of sulfur (S), 0.001-0.006 wt% of calcium (Ca), 0.01-0.06 wt% of aluminum (Al), 0.008 wt% or less of nitrogen (N), 0.6-1.2 wt% of chromium (Cr), 0.1-0.4 wt% of molybdenum (Mo), and the remaining consisting of Fe and other unavoidable impurities. COPYRIGHT KIPO 2016 ...

연료 분사관용 이음매 없는 강관

... 고강도이고, 우수한 내내압 피로 특성을 갖는 연료 분사관용 이음매 없는 강관을 제공한다. 특정의 조성과, 냉간 인발, 열처리를 행한 후의 구γ입경의 평균 입경이, 관축 방향 단면에서, 150㎛ 이하인 조직을 갖는다. 이것에 의하여, 피로 균열의 진전이 억제되어, 고분사압의 연료 분사관으로서 적합한, 인장 강도(TS): 500㎫ 이상이고, 내내압 피로 특성이 우수한 이음매 없는 강관으로 할 수 있다. 또한 상기한 조성에 더하여, 추가로 Cu, Ni, Cr, Mo, B 중으로부터 선택된 1종 또는 2종 이상, 및/또는, Ti, Nb, V 중으로부터 선택된 1종 또는 2종 이상, 및/또는, Ca를 함유해도 좋다.

HOT-ROLLED STEEL SHEET AND METHOD FOR PRODUCING SAME

HIGHLY STRONG, THICK ELECTRIC RESISTANCE-WELDED STEEL PIPE EXCELLENT IN QUENCHING PROPERTY, HOT FORMING PROCESSABILITY AND FATIGUE STRENGTH, AND METHOD FOR MANUFACTURE THEREOF

Disclosed is a highly strong, thick electric resistance-welded steel pipe excellent in quenching property, hot forming processability and fatigue strength. Also disclosed is a method for manufacture of the steel pipe. A thick electric resistance-welded steel pipe having the following composition: C: 0.25-0.4%; Si: 0.01-0.50%; Mn: 0.8-1.5%; p: 0.05% or less; S: 0.05% or less; Al: 0.05% or less; Ti: 0.005-0.05%; B: 0.0005-0.01%; and N: 0.001-0.005%, by mass, with the remainder comprising Fe and unavoidable impurities, has a critical cooling rate (Vc) represented by the formula <1> of less than 30°C/s, and the ratio of the thickness (t) to the outer diameter (D) (t/D) falling within the range of exceeding 0.15 and up to 0.30: logVc = 2.94-0.75F <1> wherein F = 2.7C + 0.4Si + Mn. © KIPO & WIPO 2008 ...

MATERIAL STEEL OF HIGH TENACITY AND PROCEDURE TO PRODUCE STEEL TUBES USING THE SAME

Se proveen un material acero y un tubo de acero fabricado con dicho material acero para ser usado en ambientes severos de pozos petrolíferos. Dicho tubo de acero para pozo petrolífero con elevada tenacidad puede ser producido laminando el material base, enfriando rápidamente el producto laminado desde la región de austenita, y reviniendo el mismo de manera que la relación entre el contenido de Mo [Mo] en los carburos precipitados en los contornos de los granos de austenita y el tamano de granos de austenita (según normas ASTM E 112), pueden ser definidos por la fórmula: [Mo] < exp(G - 5) + 5. De esta manera pueden producirse tubos de acero adecuados para uso aún en ambientes de pozos petrolíferos más y más severos, que al mismos tiempo satisfacen los requerimientos de racionalización de costos, mejora de la productividad y ahorro de energía.

tubo de aço inoxidável duplex sem costura e método para fabricar o mesmo

HIGH STRENGTH STEEL PIPE, SEAMLESS, FOR USE IN OIL WELL AND METHOD FOR PRODUCING SAME

Se provee un tubo de acero sin costura de alta resistencia para su uso en pozos de petróleo con una resistencia superior a la fisuración bajo tensión por sulfuros. El tubo de acero sin costura contiene, en % en masa. C: de 0,20% a 0.50%, Si: de 0,05% a 0,40%, Mn: de 0.3% a 0.9%, Al: de 0.005% a 0.1%, y N: 0.006% o menos, Cr: más de 0.6% y 1.7% o menos, Mo: más de 1.0% y 3.0% o menos, V: de 0.02% a 0.3%. Nb: de 0.001% a 0,02%, B: de 0,0003% a 0,0030%, O (oxígeno): 0,0030% o menos, y Ti: de 0.003% a 0.025%, donde se cumple con Ti/N: de 2,0 a 5,0, una fracción de volumen de una fase martensítica revenida es del 95% o más, los granos de austenita previa presentan un numero de tamaño de grano de 8,5 o más, y en un corte transversal perpendicular a un sentido de laminado, la cantidad de inclusiones a base de nitruro con un tamaño de grano de 4 mm o más es de 100 o menos por cada 100 mm², la cantidad de inclusiones a base de nitruro con un tamaño de grano de menos de 4 mm es de 1.000 o menos por ...

STEEL TUBES WITHOUT SEAM OF HEAVY WALL WITH EXCELLENT TENACITY TO LOW TEMPERATURE AND RESISTANCE TO THE FRACTURE BY CORROSION IN THE PRESENCE OF SULFIDES AND METHOD OF MANUFACTURE OF THE SAME

Reivindicación 1: Un tubo de acero sin costura de pared gruesa, caracterizado porque comprende: una composición de acero que comprende: 0.05% en peso a 0.16% en peso de carbono; 0.20% en peso a 0.90% en peso de manganeso; 0.10% en peso a 0.50% en peso de silicio; 1.20% en peso a 2.60% en peso de cromo; 0.05% en peso a 0.50% en peso de níquel; 0.80% en peso a 1.20% en peso de molibdeno; 0.005% en peso a 0.12% en peso de vanadio 0.008% en peso a 0.04% en peso de aluminio; 0.0030% en peso a 0.0120% en peso de nitrógeno; y 0.0010% en peso a 0.005% en peso de calcio; en tanto el espesor de pared del tubo de acero es mayor o igual a 35 mm.; y en tanto el tubo de acero se procesa de modo que posea una resistencia a la fluencia de 450 MPa o mayor y la microestructura del tubo de acero comprende martensita a un porcentaje en volumen mayor o igual a 50% y bainita inferior a un porcentaje en volumen menor o igual a 50%.Reivindicación 15: Un método de fabricación de un tubo de acero de pared gruesa ...

Bent metal member and a method for its manufacture

A bent metal member which is obtained by bending accompanied by heat treatment of a zinc-based coated metal material and which is suitable for use in components of automobiles due to having a high strength and excellent post-painting corrosion resistance is manufactured. The outer surface of a tubular metal material having on its surface a Zn—Fe alloy coating layer with a coating weight of 30-90 g/m 2 per side, an Fe content of 8-20%, and a surface roughness Ra of at most 0.8 μm is supported at two locations spaced in the axial direction of the metal material so that the material can move in its axial direction, the metal material is heated between the two locations to a temperature range of at least the Ac 3 point at a heating speed such that the rate of temperature increase is at least 3.0×10 2 ° C. per second while feeding the metal material in its axial direction, holding so that the length of time for which the surface of the metal material is at 8.0×10 2 ° C. or higher is at most 2 seconds, then rapid cooling is carried out, and the position of the downstream of the two locations in the feed direction of the metal material is two-dimensionally or three-dimensionally varied to impart a bending moment to the heated portion of the metal material. A bent metal member having a Zn-based layer which contains an η phase and which has a coating weight of 30-90 g/m 2 per side, an Fe content of 8-35%, 35%, and a surface roughness Ra of at most 2.0 μm can be manufactured.

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.

Austenitic stainless steel pipe excellent in steam oxidation resistance and manufacturing method therefor

There is provided an austenitic stainless steel pipe excellent in steam oxidation resistance. The austenitic stainless steel pipe excellent in steam oxidation resistance contains, by mass percent, 14 to 28% of Cr and 6 to 30% of Ni, and is configured so that a region satisfying the following Formula exists in a metal structure at a depth of 5 to 20 μm from the inner surface of the steel pipe: (α/β)×δ/ε×100≧0.3 where the meanings of symbols in the above Formula are as follows: α: sum total of the number of pixels of digital image in region in which orientation difference of adjacent crystals detected by electron backscattering pattern is 5 to 50 degrees β: the number of total pixels of digital image in region of measurement using electron backscattering pattern ε: analysis pitch width of electron backscattering pattern (μm) δ: grain boundary width (μm).

Automobile chassis part excellent in low cycle fatigue characteristics and method of production of same

An automobile chassis part which is excellent in low cycle fatigue characteristics, characterized by being formed by steel which contains, by mass %, C: 0.02 to 0.10%, Si: 0.05 to 1.0%, Mn: 0.3 to 2.5%, P: 0.03% or less, S: 0.01% or less, Ti: 0.005 to 0.1%, Al: 0.005 to 0.1%, N: 0.0005 to 0.006%, and B: 0.0001 to 0.01 and has a balance of Fe and unavoidable impurities, in which 80% or more of the part structure comprises a bainite structure and in which a portion where a ratio R/t of the thickness “t” and external surface curvature radius R is 5 or less has an X-ray half width of an (211) plane of 5 (deg) or less.

AUSTENITIC HIGH MN STAINLESS STEEL AND METHOD PRODUCTION OF SAME AND MEMBER USING THAT STEEL

Inexpensive stainless steel and inexpensive and high strength stainless steel which has excellent hydrogen environment embrittlement resistance even if used in a hydrogen resistant environment in over 40 MPa high pressure hydrogen gas or a hydrogen resistant environment in liquid hydrogen, characterized by containing, by mass %, C: 0.1% or less, Si: 0.4 to 1.5%, Mn: 8 to 11%, Cr: 15 to 17%, Ni: 5 to 8%, Cu: 1 to 4%, and N: 0.01 to less than 0.15% and having a balance of Fe and unavoidable impurities, having a volume rate of δ-ferrite of 10% or less, and having a long axis of δ-ferrite before annealing of 0.04 to 0.1 mm. 114.-. (canceled)15. Austenitic high Mn stainless steel characterized by containing , by mass % , C: 0.1% or less , Si: 0.4 to 1.5% , Mn: 8 to 11% , Cr: 15 to 17% , Ni: 5 to 8% , Cu: 1 to 4% , Mo: 0.05 to 0.3% , and N: 0.01 to less than 0.15% and having a balance of Fe and unavoidable impurities , having a volume rate of δ-ferrite of 5% or less , and having a long axis of δ-ferrite of 0.05 mm or less.16. Austenitic high Mn stainless steel characterized by containing , by mass % , C: 0.1% or less , Si: 0.4 to 1.5% , Mn: 8 to 11% , Cr: 15 to 17% , Ni: 6 to 8% , Cu: 1 to 4% , Mo: 0.05 to 0.3% , and N: 0.15 to 0.3% and having a balance of Fe and unavoidable impurities , having a volume rate of δ-ferrite of 5% or less , and having a long axis of δ-ferrite of less than 0.05 mm.17. The austenitic high Mn stainless steel as set forth in characterized in that said steel further contains claim 15 , by mass % claim 15 , one or more types of elements selected from Al: 0.2% or less claim 15 , B: 0.01% or less claim 15 , Ca: 0.01% or less claim 15 , Mg: 0.01% or less claim 15 , and REM: 0.1% or less.18. The austenitic high Mn stainless steel as set forth in characterized in that said steel further contains claim 16 , by mass % claim 16 , one or more types of elements selected from Al: 0.2% or less claim 16 , B: 0.01% or less claim 16 , Ca: 0.01% or less claim 16 , ...

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.

Low C-High CR 862 MPA-Class Steel Tube Having Excellent Corrosion Resistance and a Manufacturing Method Thereof

A purpose of the present invention is to provide a martensitic stainless steel tube exhibiting excellent performance even in severe corrosive environments in which a partial pressure of hydrogen sulfide exceeds 0.03 bar. 1. A low C-high Cr steel tube having minimum yield strength of 862 MPa and excellent corrosion resistance , wherein said steel tube contains , in percent by mass , 0.005 to 0.05% C , 12 to 16% Cr , 1.0% or less Si , 2.0% or less Mn , 3.5 to 7.5% Ni , 1.5 to 3.5% Mo , 0.01 to 0.05% V , 0.02% or less N , and 0.01 to 0.06% Ta and satisfies the relationship in the following formula (1) , and the rest comprises Fe and unavoidable impurities.{'br': None, '25-25 (% Ni)+5 (% Cr)+25 (% Mo)≧0\u2003\u2003(1)'}2. The low C-high Cr steel tube having minimum yield strength of 862 MPa and excellent corrosion resistance according to claim 1 , wherein said steel tube further contains 0.1% or less Nb in percent by mass.3. A manufacturing method of a low C-high Cr steel tube having minimum yield strength of 862 MPa and excellent corrosion resistance claim 1 , wherein after hot working of a low C-high Cr steel having the composition according to claim 1 , the low C-high Cr steel is austenitized at the temperature between the Ac3 transformation point and 980° C. claim 1 , then cooled to the temperature of 100° C. or less followed by tempering at the temperature between 500° C. and 700° C.4. A manufacturing method of a low C-high Cr steel tube having minimum yield strength of 862 MPa and excellent corrosion resistance claim 2 , wherein after hot working of a low C-high Cr steel having the composition according to claim 2 , the low C-high Cr steel is austenitized at the temperature between the Ac3 transformation point and 980° C. claim 2 , then cooled to the temperature of 100° C. or less followed by tempering at the temperature between 500° C. and 700° C. The present invention relates to a low C-high Cr steel tube having minimum yield strength of 862 MPa and excellent ...

AUSTENITIC ALLOY PIPE AND METHOD FOR PRODUCING THE SAME

There is provided an austenitic alloy pipe that is durable even if a stress distribution different according to usage environment is applied. The austenitic alloy pipe in accordance with the present invention has a tensile yield strength YSof at least 689.1 MPa. The tensile yield strength YS, a compressive yield strength YSin a pipe axial direction, a tensile yield strength YSin a pipe circumferential direction of the alloy pipe, and a compressive yield strength YSin the pipe circumferential direction satisfy Formulas () to (). 1. An austenitic alloy pipe , wherein{'sub': 'LT', 'a tensile yield strength YSin a pipe axial direction of the alloy pipe is at least 689.1 MPa; and'}{'sub': LT', 'LC', 'CT', 'CC, 'claim-text': [{'br': None, 'sub': LC', 'LT, '0.90≦YS/YS≦1.11\u2003\u2003(1)'}, {'br': None, 'sub': CC', 'CT, '0.90≦YS/YS≦1.11\u2003\u2003(2)'}, {'br': None, 'sub': CC', 'LT, '0.90≦YS/YS≦1.11\u2003\u2003(3)'}, {'br': None, 'sub': CT', 'LT, '0.90≦YS/YS≦1.11\u2003\u2003(4)'}], 'the tensile yield strength YS, a compressive yield strength YSin the pipe axial direction, a tensile yield strength YSin a pipe circumferential direction of the alloy pipe, and a compressive yield strength YSin the pipe circumferential direction satisfy Formulas (1) to (4).'}2. The austenitic alloy pipe according to claim 1 , comprising claim 1 , by mass percent claim 1 , of C: at most 0.03% claim 1 , Si: at most 1.0% claim 1 , Mn: 0.3 to 5.0% claim 1 , Ni: 23 to 52% claim 1 , Cr: 20 to 30% claim 1 , N: 0.005 to 0.50% claim 1 , Mo: at most 9% claim 1 , and Cu: at most 3% claim 1 , the balance being Fe and impurities.3. The austenitic alloy pipe according to claim 2 , comprising claim 2 , in place of some of the Fe claim 2 , at least one type selected from a group consisting claim 2 , by mass percent claim 2 , of Ca: at most 0.01% claim 2 , Mg: at most 0.01% claim 2 , and REM (rare earth metal): at most 0.20%.4. The austenitic alloy pipe according to claim 1 , which is produced by being ...

Electric resistance welded steel pipe for producing hollow stabilizer, hollow stabilizer, and production methods for same

There are provided an electric resistance welded steel pipe for producing a high strength hollow stabilizer excellent in fatigue resistance and a high strength hollow stabilizer. In an electric resistance welded steel pipe (5) for producing a hollow stabilizer, an internal weld bead cut portion (30) has a three-peak shape and a depth (H) of a trough portion (30a) of the three-peak shape is 0.3 mm or less and an angle (θ) formed by a central portion in the circumferential direction of the trough portion (30a) and the top of right and left peak portions (30b, 30c) located on both the right and left sides of the trough portion (30a) is 160° or more and less than 180°.

TITANIUM-FREE ALLOY

Titanium-free alloy which has great resistance to pitting and crevice corrosion and a high yield point in the strain-hardened state and includes (in wt %) a maximum of 0.02% C, a maximum of 0.01% S, a maximum of 0.03% N, 20.0-23.0% Cr, 39.0-44.0% Ni, 0.4-<1.0% Mn, 0.1-<0.5% Si, >4.0-<7.0% Mo, a maximum of 0.15% Nb, >1.5-<2.5% Cu, 0.05-<0.3% Al, a maximum of 0.5% Co, 0.001-<0.005% B, 0.005-<0.015% Mg, the remainder consisting of Fe and smelting-related impurities. 4: Alloy according to claim 1 , which if necessary contains (in wt %) V>0-1.0% claim 1 , especially 0.2-0.7%.5: Process for the manufacture of an alloy that has a composition according to claim 1 , whereina) the alloy is melted openly in continuous or ingot casting,b) to eliminate the segregations caused by the increased molybdenum content, a homogenizing annealing of the produced blooms/billets is performed at 1150-1250° C. for 15 to 25 h, whereinc) the homogenizing annealing is performed in particular following a first hot forming.6: Use of the alloy according to as a structural part in the oil and gas industry.7: Use according to claim 6 , wherein the structural parts exist in the production forms sheet claim 6 , strip claim 6 , pipe (longitudinally welded and seamless) claim 6 , bar or as forging. The invention relates to a titanium-free alloy with high pitting and crevice corrosion resistance as well as high offset yield strength and tensile strength in the cold-worked condition.The high-corrosion-resistant material Alloy 825 is used for critical applications in the chemical industry and in the offshore technology. It is marketed under the material number 2.4858 and has the following chemical composition: C≦0.025%, S≦0.015%, Cr 19.5-23.5%, Ni 28-46%, Mn≦1%, Si≦0.5%, Mo 2.5-3.5%, Ti 0.6-1.2%, Cu 1.5-3%, Al≦0.2%, Co≦1%, Fe the rest.For new applications in the oil and gas industry, the pitting and crevice corrosion resistance (problem 1) as well as the offset yield strength and tensile strength (problem 2 ...

HOLLOW METAL SCREW AND METHOD OF MAKING

A hollow screw and related process of making is provided, wherein the hollow screw is formed from a generally circular corrosion resistant stainless steel disk cut from flat roll stock. The hollow screw includes a head and an elongated and hollow shaft having a wall thickness between about 0.2 to about 0.7 millimeters extending therefrom and defining a shank portion and a threaded portion having a plurality of threads thereon with a rotational drive mechanism configured to facilitate tightening via the threads. The process involves annealing to soften the stamped hollow screw, followed by thread rolling, and then age hardening the hollow screw. As such, the resultant hollow screw is relatively lightweight, about 50% the mass of a solid core screw made from the same material, with a sufficient thread strength to meet most aerospace applications and contributes to important aircraft fuel economy. 1. A hollow screw , comprising:a head formed from a flat stock of metal material;an elongated and hollow shaft formed from the flat stock of metal material and integrally extending from the head, the elongated and hollow shaft including a shank portion and a threaded portion having a plurality of threads thereon; anda rotational drive mechanism integrally formed from the flat stock of metal material and coupled with the head or the elongated and hollow shaft, and configured to facilitate tightening of the hollow screw by way of the threads.2. The hollow screw of claim 1 , wherein the elongated and hollow shaft comprises a wall thickness between about 0.2 and 0.7 millimeters.3. The hollow screw of claim 1 , including an integral washer formed from the flat stock of metal material and extending outwardly from the head.4. The hollow screw of claim 3 , including a captive washer at least partially formed around the integral washer in a manner permitting free rotation of the captive washer relative to the integral washer claim 3 , the head and the elongated and hollow shaft.5. The ...

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 ...

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 THE PRODUCTION OF A SEAMLESS, MULTILAYERED TUBULAR PRODUCT, AND ROUND OR POLYGONAL BLOCK FOR USE IN THIS METHOD

In a method for the production of a seamless, multilayered tubular product, a further layer is applied through hardfacing on a base layer of a round or polygonal block, with the further layer made of a metallic material which is different than a metallic material of the base layer. The round or polygonal block with hardfaced further layer is hot formed to produce a tubular product with reduced wall thickness and outer perimeter in one or more stages. A diffusion layer is established between the base layer and the further layer through heat treatment before hot forming and/or after hot forming, thereby producing a thickness of the diffusion layer of at least 5 μm with the proviso that the thickness of the diffusion layer is 0.1% to 50% of a thickness of the further layer, with the thickness of the further layer being equal to or greater than 100 μm. 1. A method for the production of a seamless , multilayered tubular product , comprising:hardfacing a further layer on a base layer of a round or polygonal block, with the further layer being made of a metallic material which is different than a metallic material of the base layer;hot forming the round or polygonal block with hardfaced further layer to produce a tubular product with reduced wall thickness and outer perimeter in one or more stages; andestablishing a diffusion layer between the base layer and the further layer through heat treatment at least in one of the phases selected from the group consisting of before hot forming and after hot forming, thereby producing a thickness of the diffusion layer of at least 5 μm on the tubular product, with the proviso that the thickness of the diffusion layer is 0.1% to 50% of a thickness of the further layer on the tubular product, with the thickness of the further layer being equal to or greater than 100 μm.2. The method of claim 1 , wherein the round or polygonal block is heat treated without subjecting the further layer to a material removing process claim 1 , and ...

ENDLESS METAL RING MANUFACTURING METHOD AND ENDLESS METAL RING RESIN REMOVAL DEVICE

Provided is an endless metal ring manufacturing method for manufacturing an endless metal ring by carrying out a barrel polishing step for polishing the endless metal ring by using a barrel of a resin material, a rolling step for rolling the endless metal ring which was cleaned, and a nitriding step for nitriding the endless metal ring which was rolled, wherein after the barrel polishing step and before the rolling step, provided is a resin removing step for removing resin that has adhered to the endless metal ring. 1a barrel polishing step of polishing an endless metal ring by use of a barrel made of resin;a rolling step of rolling the endless metal ring having been washed; anda nitriding step of nitriding the rolled endless metal ring,wherein the manufacturing method further includes a resin removal step of removing the resin that has adhered to the endless metal ring,the resin removal step is performed after the barrel polishing step and before the rolling step,the resin removal step includes soaking the endless metal ring into a liquid to perform ultrasonic washing; andthe resin removal step includes rotating the endless metal ring in a circumferential direction about an axis of the endless metal ring to wash the endless metal ring.. An endless metal ring manufacturing method including: This application is a division of U.S. application Ser. No. 14/765,185 filed Jul. 31, 2015, the entire contents of which is incorporated herein by reference. U.S. application Ser. No. 14/765,185 is a 371 of International Application No. PCT/JP2013/063260 filed May 13, 2013.The present invention relates to a method of manufacturing an endless metal ring for constituting a laminated ring mounted in a CVT belt, and relates to a technique of preventing generation of nitriding failure during manufacturing of the endless metal ring by improving a washing process and a washing method.In recent years, there have been increased vehicles provided with a continuously variable transmission ( ...

ENDLESS METAL RING MANUFACTURING METHOD AND ENDLESS METAL RING RESIN REMOVAL DEVICE

Provided is an endless metal ring manufacturing method for manufacturing an endless metal ring by carrying out a barrel polishing step for polishing the endless metal ring by using a barrel of a resin material, a rolling step for rolling the endless metal ring which was cleaned, and a nitriding step for nitriding the endless metal ring which was rolled, wherein after the barrel polishing step and before the rolling step, provided is a resin removing step for removing resin that has adhered to the endless metal ring. 1. An endless metal ring resin removal device configured to wash and hold the endless metal ring , a holding tool for holding the endless metal ring;', 'a rotation mechanism configured to rotate the endless metal ring in a circumferential direction of the endless metal ring with the holding tool;', 'a washing tank filled with a liquid for ultrasonic washing of the endless metal ring; and', 'an ultrasonic wave generator for performing the ultrasonic washing., 'wherein the endless metal ring resin removal device includes2. The endless metal ring resin removal device according to claim 1 , wherein the ultrasonic washing device is operated while the rotation mechanism rotates the endless metal ring in the circumferential direction to remove resin having adhered to a surface of the endless metal ring. This application is a division of U.S. application Ser. No. 14/765,185 filed Jul. 31, 2015, the entire contents of which is incorporated herein by reference. U.S. application Ser. No. 14/765,185 is a 371 of International Application No. PCT/JP2013/063260 filed May 13, 2013.The present invention relates to a method of manufacturing an endless metal ring for constituting a laminated ring mounted in a CVT belt, and relates to a technique of preventing generation of nitriding failure during manufacturing of the endless metal ring by improving a washing process and a washing method.In recent years, there have been increased vehicles provided with a continuously ...

A PROCESS OF PRODUCING A DUPLEX STAINLESS STEEL TUBE

A process of producing a duplex stainless steel tube comprises the steps of: 2. A process according to claim 1 , wherein claim 1 , if 0 Подробнее

FERRITIC STAINLESS STEEL AND FERRITIC STAINLESS STEEL PIPE WITH IMPROVED MECHANICAL PROPERTIES OF WELDING PORTION

A ferritic stainless steel with improved mechanical properties of weld zone is disclosed. The ferritic stainless steel includes, in percent (%) by weight of the entire composition, C: 0.005 to 0.02%, N: 0.005 to 0.02%, Cr: 11.0 to 13.0%, Ti: 0.16 to 0.3%, Nb: 0.1 to 0.3%, Al: 0.005 to 0.05%, the remainder of iron (Fe) and other inevitable impurities, and the ferritic stainless steel has a texture maximum strength of 30 or less in the {001} direction after welding. 1. A ferritic stainless steel with improved mechanical properties of weld zone , the ferritic stainless steel comprising , in percent (%) by weight of the entire composition , C: 0.005 to 0.02% , N: 0.005 to 0.02% , Cr: 11.0 to 13.0% , Ti: 0.16 to 0.3% , Nb: 0.1 to 0.3% , Al: 0.005 to 0.05% , the remainder of iron (Fe) and other inevitable impurities , andthe ferritic stainless steel has a texture maximum strength of 30 or less in the {001} direction after welding.2. The ferritic stainless steel according to claim 1 , wherein the ferritic stainless steel comprises a secondary phase present in the weld zone of 10 to 100 pieces/mmafter welding.3. The ferritic stainless steel according to claim 2 , wherein the secondary phase comprises nitride claim 2 , oxide and Laves phase precipitates.4. The ferritic stainless steel according to claim 1 , further comprising: at least one of Mo: 1.0% or less claim 1 , Ni: 1.0% or less claim 1 , Cu: 1.0% or less claim 1 , and B: 0.005% or less.5. A ferritic stainless steel pipe comprising:a base material comprising, in percent (%) by weight of the entire composition, C: 0.005 to 0.02%, N: 0.005 to 0.02%, Cr: 11.0 to 13.0%, Ti: 0.16 to 0.3%, Nb: 0.1 to 0.3%, Al: 0.005 to 0.05%, the remainder of iron (Fe) and other inevitable impurities, anda weld zone having a texture maximum strength of 30 or less in the {001} direction.6. The ferritic stainless steel pipe according to claim 5 , wherein the weld zone comprises a secondary phase of 10 to 100/mm.7. The ferritic stainless steel ...

MARTENSITIC STAINLESS SEAMLESS STEEL PIPE

The seamless steel pipe according to the present disclosure includes a chemical composition consisting of, in mass %, C: 0.030% or less, Si: 1.00% or less, Mn: 1.00% or less, P: 0.030% or less, S: 0.0050% or less, Al: 0.001 to 0.100%, N: 0.0500% or less, O: 0.050% or less, Ni: 3.00 to 6.50%, Cr: more than 10.00 to 13.40%, Mo: 0.50 to 4.00%, V: 0.01 to 1.00%, Ti: 0.010 to 0.300%, and Co: 0.010 to 0.300%, with the balance being Fe and impurities, and satisfying Formula (1), and a microstructure containing, in volume ratio, 80.0% or more of martensite, wherein a depassivation pH of an inner surface is 3.50 or less. 14-. (canceled)5. A martensitic stainless seamless steel pipe comprising:a chemical composition consisting of, in mass %,C: 0.030% or less,Si: 1.00% or less,Mn: 1.00% or less,P: 0.030% or less,S: 0.0050% or less,Al: 0.001 to 0.100%,N: 0.0500% or less,O: 0.050% or less,Ni: 3.00 to 6.50%,Cr: more than 10.00 to 13.40%,Mo: 0.50 to 4.00%,V: 0.01 to 1.00%,Ti: 0.010 to 0.300%,Co: 0.010 to 0.300%,Ca: 0 to 0.0035%,W: 0 to 1.50%, andwith the balance being Fe and impurities, and satisfying Formula (1), anda microstructure containing, in volume ratio, 80.0% or more of martensite, wherein{'sub': 3', '3, 'claim-text': {'br': None, 'Cr+2.0Mo+0.5Ni+0.5Co≥16.0\u2003\u2003(1)'}, 'an inner surface of the martensitic stainless seamless steel pipe has a depassivation pH of 3.50 or less in an aqueous solution that contains 5 mass % of NaCl and 0.41 g/L of CHCOONa and further contains CHCOOHwhere, a content of a corresponding element (in mass %) is substituted for each symbol of an element in Formula (1).6. The martensitic stainless seamless steel pipe according to claim 5 , whereinthe chemical composition contains:Ca: 0.0010 to 0.0035%.7. The martensitic stainless seamless steel pipe according to claim 5 , whereinthe chemical composition contains:W: 0.10 to 1.50%.8. The martensitic stainless seamless steel pipe according to claim 6 , whereinthe chemical composition contains:W: 0. ...

A PROCESS OF PRODUCING AN AUSTENITIC STAINLESS STEEL TUBE

A process of producing an austenitic stainless steel tube comprises the steps of: 2. A process according to claim 1 , wherein 50%≤Rc.3. A process according to claim 1 , wherein Rc≤68%.4. A process according to claim 1 , wherein 60%≤Rh.5. A process according to claim 1 , wherein Rh≤80%.6. A process according to claim 1 , wherein 1.5≤Q.7. A process according to claim 1 , wherein Q≤3.2.9. A process according to claim 1 , wherein 50≤Rc≤68% claim 1 , wherein 60%≤Rh≤80% claim 1 , and wherein 1.5≤Q≤3.2. The present disclosure relates to a process of producing an austenitic stainless steel tube.Stainless steel tubes having the composition defined herein are used in a wide variety of applications in which they are subjected to corrosive media as well as substantive mechanical load. During the production of such stainless steel tubes, different process parameters have to be set correctly in order to obtain a steel tube having the desired yield strength. Process parameters that have been found to have important impact on the final yield strength of the material of the tube are the following: degree of hot deformation, degree of cold deformation and ratio between tube diameter and tube wall reduction during the process in which a hot extruded tube is cold rolled to its final dimensions. These process parameters have to be set with regard to the specific composition of the austenitic stainless steel and the desired yield strength of the stainless steel tube.Up to this point, prior art has relied upon performing extensive trials in order to find process parameter values resulting in the achievement of a target yield strength of austenitic stainless steel tubes. Such trials are laborious and costly. Therefore, a more cost-efficient process for determining process parameters crucial to the yield strength is desirable.EP 2 388 341 suggests a process for producing a duplex stainless steel tube having a specific chemical composition, wherein the working ratio (%) in terms of reduction ...

Flat steel semi-finished product, method for producing a component, and use thereof

A semifinished flat steel product (1) includes a first layer (1.1) of a martensitic steel alloy having a tensile strength of >1200 MPa and/or a hardness of >370 HV10, and at least one second layer (1.2, 1.2′) of a soft steel alloy having a tensile strength of <600 MPa and/or a hardness of <190 HV10 which is fully and cohesively bonded to the first layer (1.1).

COILED TUBE WITH VARYING MECHANICAL PROPERTIES FOR SUPERIOR PERFORMANCE AND METHODS TO PRODUCE THE SAME BY A CONTINUOUS HEAT TREATMENT

Described herein are coiled tubes with improved and varying properties along the length that are produced by using a continuous and dynamic heat treatment process (CDHT). Coiled tubes can be uncoiled from a spool, subjected to a CDHT process, and coiled onto a spool. A CDHT process can produce a “composite” tube such that properties of the tube along the length of the tube are selectively varied. For example, the properties of the tube can be selectively tailored along the length of the tube for particular application for which the tube will be used. 1. A method of treating a tube , the method comprising:providing a spool of the tube;uncoiling the tube from the spool;heat treating the uncoiled tube to provide varied properties along a length of the uncoiled tube; andcoiling the tube after heat treating.2. The method of claim 1 , wherein the varied properties includes mechanical properties.3. The method of claim 1 , wherein at least one of temperature claim 1 , soak time claim 1 , heating rate claim 1 , and cooling rate is varied during heat treating of the uncoiled tube to provide varied properties along the length of the uncoiled tube.4. The method of claim 1 , wherein the tube has a substantially constant wall thickness throughout the tube.5. The method of claim 1 , wherein during the heat treating the uncoiled tube is moved at variable speeds.6. The method of claim 1 , wherein the heat treating is continuous and controlled over the length of the uncoiled tube.7. The method of claim 6 , wherein the tube undergoes continuous and controlled heat treating in every portion along its entire length between a first end and the second end to provide a tempered martensite microstructure with varying yield strengths to the entire length of the coiled tube.8. The method of claim 1 , wherein the heat treating modifies the microstructure of the uncoiled tube to form at least two sections having different yield strengths.9. The method of claim 8 , wherein the at least two ...

SEAMLESS STEEL TUBE FOR FUEL INJECTION

A seamless steel tube has a particular composition and a structure with an average prior γ grain size of 150 μm or less in an axial cross-section after cold drawing and heat treatment. The structure retards the growth of a fatigue crack. The steel tube has a tensile strength TS of 500 MPa or more and good internal pressure fatigue resistance and is suitable for use as a fuel injection tube under high injection pressures. The composition of the steel tube may further contain at least one of Cu, Ni, Cr, Mo, and B; at least one of Ti, Nb, and V; and/or Ca. 14-. (canceled)6. The seamless steel tube according to claim 5 , wherein the composition further comprises claim 5 , by mass claim 5 , at least one of 0.70% or less Cu claim 5 , 1.00% or less Ni claim 5 , 1.20% or less Cr claim 5 , 0.50% or less Mo claim 5 , and 0.0060% or less B.7. The seamless steel tube according to claim 5 , wherein the composition further comprises claim 5 , by mass claim 5 , at least one of 0.20% or less Ti claim 5 , 0.050% or less Nb claim 5 , and 0.20% or less V.8. The seamless steel tube according to claim 6 , wherein the composition further comprises claim 6 , by mass claim 6 , at least one of 0.20% or less Ti claim 6 , 0.050% or less Nb claim 6 , and 0.20% or less V.9. The seamless steel tube according to claim 5 , wherein the composition further comprises claim 5 , by mass claim 5 , 0.0040% or less Ca.10. The seamless steel tube according to claim 6 , wherein the composition further comprises claim 6 , by mass claim 6 , 0.0040% or less Ca.11. The seamless steel tube according to claim 7 , wherein the composition further comprises claim 7 , by mass claim 7 , 0.0040% or less Ca.12. The seamless steel tube according to claim 8 , wherein the composition further comprises claim 8 , by mass claim 8 , 0.0040% or less Ca. This disclosure relates to seamless steel tubes suitable as fuel injection tubes injecting fuel into combustion chambers such as those of diesel engines. In particular, the ...

HIGH-STRENGTH HEAVY-WALLED STAINLESS STEEL SEAMLESS TUBE OR PIPE AND METHOD OF MANUFACTURING THE SAME

A high-strength heavy-walled stainless steel seamless tube or pipe exhibiting excellent low-temperature toughness is characterized by having a chemical composition containing Cr: 15.5% to 18.0% and a steel microstructure containing a ferritic phase and a martensitic phase, wherein the maximum value of the areas of the ferrite grains in the steel microstructures in a circumferential direction cross section and an L direction (rolling direction) cross section of the steel tube or pipe is 3,000 μmor less and the content of ferrite grains having areas of 800 μmor less is 50% or more on an area fraction basis, where, when adjacent ferrite grains are present in the steel microstructure and the crystal misorientation between one ferrite grain and the other ferrite grain is 15° or more, the adjacent grains are assumed to be grains different from each other. 15.-. (canceled)6. A high-strength heavy-walled stainless steel seamless tube or pipe with excellent low-temperature toughness ,comprising a chemical composition containing, on a percent by mass basis, Cr: 15.5% to 18.0% and a steel microstructure containing a ferritic phase and a martensitic phase,{'sup': 2', '2, 'wherein a maximum value of areas of ferrite grains in the steel microstructures in a circumferential direction cross section and an L direction (rolling direction) cross section of the steel tube or pipe is 3,000 μmor less and content of ferrite grains having areas of 800 μmor less is 50% or more on an area fraction basis, where, when adjacent ferrite grains are present in the steel microstructure and crystal misorientation between one ferrite grain and another ferrite grain is 15° or more, the adjacent grains are grains different from each other.'}7. The high-strength heavy-walled stainless steel seamless tube or pipe according to claim 6 , wherein the chemical composition further contains claim 6 , on a percent by mass basis claim 6 , C: 0.050% or less claim 6 , Si: 1.00% or less claim 6 , Mn: 0.20% to 1.80% ...

STEEL MATERIAL SUITABLE FOR USE IN SOUR ENVIRONMENT

A steel material according to the present disclosure has a chemical composition consisting of, in mass %: C: 0.15 to 0.45%, Si: 0.05 to 1.00%, Mn: 0.01 to 1.00%, P: 0.030% or less, S: 0.0050% or less, Al: 0.005 to 0.100%, Cr 0.55 to 1.10%, Mo: 0.70 to 1.00%, Ti: 0.002 to 0.020%, V: 0.05 to 0.30%, Nb: 0.002 to 0.100%, B: 0.0005 to 0.0040%, N: 0.0100% or less, O: less than 0.0020%, and the balance being Fe and impurities, and satisfying Formula (1) described in the specification. A grain diameter of a prior-austenite grain is 15.0 μm or less, and an average area of precipitate which is precipitated in a prior-austenite grain boundary is 12.5×10μmor less. A yield strength is 758 to 862 MPa. 16-. (canceled)7. A steel material comprising:a chemical composition consisting of, in mass %:C: 0.15 to 0.45%,Si: 0.05 to 1.00%,Mn: 0.01 to 1.00%,P: 0.030% or less,S: 0.0050% or less,Al: 0.005 to 0.100%,Cr: 0.55 to 1.10%,Mo: 0.70 to 1.00%,Ti: 0.002 to 0.020%,V: 0.05 to 0.30%,Nb: 0.002 to 0.100%,B: 0.0005 to 0.0040%,N: 0.0100% or less,O: less than 0.0020%,Ca: 0 to 0.0100%,Mg: 0 to 0.0100%,Zr 0 to 0.0100%,rare earth metal: 0 to 0.0100%,Cu: 0 to 0.50%,Ni: 0 to 0.50%,Co: 0 to 0.50%, andW: 0 to 0.50%,with the balance being Fe and impurities,and satisfying Formula (1),whereinin the steel material, a grain diameter of a prior-austenite grain is 15.0 μm or less,{'sup': −3', '2, 'an average area of precipitate which is precipitated in a prior-austenite grain boundary is 12.5×10μmor less, and'} {'br': None, 'Mo/Cr≥0.90\u2003\u2003(1)'}, 'a yield strength is 758 to 862 MPawhere, content in mass % of a corresponding element is substituted for each symbol of an element in Formula (1).8. The steel material according to claim 7 , whereinthe 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%,Zr: 0.0001 to 0.0100%, andrare earth metal: 0.0001 to 0.0100%.9. The steel material according to claim 7 , whereinthe ...

HIGH-STRENGTH SEAMLESS STEEL PIPE FOR OIL COUNTRY TUBULAR GOODS, AND PRODUCTION METHOD FOR HIGH-STRENGTH SEAMLESS STEEL PIPE FOR OIL COUNTRY TUBULAR GOODS

The high-strength seamless steel pipe has a volume fraction of tempered martensite of 95% or more, and a prior austenite size number of 8.5 or more, and contains nitride inclusions having a size of 4 μm or more and whose number is 100 or less per 100 mm, nitride inclusions having a size of less than 4 μm and whose number is 700 or less per 100 mm, oxide inclusions having a size of 4 μm or more and whose number is 60 or less per 100 mm, and oxide inclusions having a size of less than 4 μm and whose number is 500 or less per 100 mm, in a cross section perpendicular to a rolling direction. 15-. (canceled)6. A high-strength seamless steel pipe for oil country tubular goods of a composition comprising C: 0.20 to 0.50 mass % , Si: 0.05 to 0.40 mass % , Mn: 0.1 to 1.5 mass % , P: 0.015 mass % or less , S: 0.005 mass % or less , Al: 0.005 to 0.1 mass % , N: 0.006 mass % or less , Cr: 0.1 to 2.5 mass % , Mo: 0.1 to 1.0 mass % , V: 0.03 to 0.3 mass % , Nb: 0.001 to 0.030 mass % , B: 0.0003 to 0.0030 mass % , O (oxygen): 0.0030 mass % or less , Ti: 0.003 to 0.025 mass % , and the balance Fe and unavoidable impurities , and satisfying Ti/N=2.0 to 5.5 ,{'sup': 2', '2', '2', '2, 'wherein the high-strength seamless steel pipe has a structure in which a volume fraction of tempered martensite is 95% or more, and a prior austenite grain size number is 8.5 or more, and that contains nitride inclusions having a size of 4 μm or more and whose number is 100 or less per 100 mm, nitride inclusions having a size of less than 4 μm and whose number is 700 or less per 100 mm, oxide inclusions having a size of 4 μm or more and whose number is 60 or less per 100 mm, and oxide inclusions having a size of less than 4 μm and whose number is 500 or less per 100 mm, in a cross section perpendicular to a rolling direction, and'}wherein the high-strength seamless steel pipe has a yield strength YS of 862 MPa or more.7. The high-strength seamless steel pipe for oil country tubular goods according to ...

LOW TEMPERATURE RESISTANT OIL CASING HAVING HIGH STRENGTH AND HIGH TOUGHNESS, AND MANUFACTURING METHOD THEREOF

The present disclosure provides a low temperature resistant oil casing having high strength and high toughness, and the manufacturing method thereof, the chemical composition of the oil casing by mass of: C: 0.08-0.14%, Si: 0.1-0.4%, Mn: 0.6-1.3%, Cr: 0.5-1.5%, Mo: 0.2-0.5%, Ni: 0.2-0.5%, Nb: 0.02-0.05%, V: 0-0.1%, Al: 0.01-0.05%, Ca: 0.0005-0.005%, and the balance being Fe and unavoidable impurities. The method of manufacturing the oil casing includes: (1) smelting and continuous casting; (2) perforating and continuous rolling; (3) heat treatment, wherein an austenitizing temperature is controlled in the range of 900-930° C., and held for 30-60 min, followed by quenching, subsequently, tempering at temperature of 480-600° C., holding the temperature for 50-80 min; (4) hot sizing. 1. A low temperature resistant oil casing having high strength and high toughness , characterized by chemical composition by mass of:C: 0.08-0.14%, Si: 0.1-0.4%, Mn: 0.6-1.3%, Cr: 1-1.4%, Mo: 0.2-0.5%, Ni: 0.2-0.5%, Nb: 0.02-0.05%, V: 0-0.1%, Al: 0.01-0.05%, Ca: 0.0005-0.005%, the balance being Fe and unavoidable impurities.2. The low temperature resistant oil casing having high strength and high toughness according to claim 1 , which further satisfies the formula: 0.3 Подробнее

Seamless steel pipe heat-treatment-finishing-treatment continuous facility

A seamless steel pipe heat-treatment-finishing-treatment continuous facility includes: a heat treatment apparatus; a steel pipe inspection apparatus which performs a test for a surface defect and/or an inner defect of the seamless steel pipe, the steel pipe inspection apparatus being disposed downstream of the heat treatment apparatus; a main transfer mechanism which forms a main transfer path MT for transferring the seamless steel pipe, discharged from the heat treatment apparatus, to the steel pipe inspection apparatus disposed downstream of the heat treatment apparatus; and a first forced steel pipe-temperature reduction apparatus which forcibly reduces a temperature of the seamless steel pipe on the main transfer path MT, the first forced steel pipe-temperature reduction apparatus being disposed on the main transfer path MT at a position downstream of the heat treatment apparatus and upstream of the steel pipe inspection apparatus.

MARTENSITIC-FERRITIC STAINLESS STEEL, MANUFACTURED PRODUCT AND PROCESS USING THE S

The present invention relates to a martensitic-ferritic stainless steel with high corrosion resistance that comprises the following chemical composition: C: from 5 0.005 to 0.030%; Si: from 0.10 to 0.40%; Mn from 0.20 to 0.80%; P: 0.020% max; S: 0.005% max; Cr: from 13 to 15%; Ni: from 4.0 to 6.0%; Mo: from 2.0 to 4.5%; V: from 0.01 to 0.10%; Nb: from 0.01 to 0.50%; N: from 0.001 to 0.070%; Al: from 0.001 to 0.060%; Ti: from 0.001 to 0.050%; Cu: from 0.01 to 1.50%; O: 0.005% max (all in weight percent), wherein the balance is performed by Fe and unavoidable impurities 10 from the industrial possessing in acceptable levels. Additionally, the martensitic-ferritic stainless steel of the present invention has the localized corrosion parameter (LCP), between 3.2 and 6.2, as defined by equation below; LCP=0.500−% Cr+1.287·% Mo+1.308·% N−5.984 The present invention also relates to a manufactured product comprising the martensitic-ferritic stainless steel of the invention; to a process for 15 production of forged or rolled parts or bars; and to a process for production of seamless tube from this martensitic-ferritic stainless steel of the present invention, wherein the processes of the invention have a heating temperature in determined step following the equation below: T−16.9*% Cr−49.9*% Mo>535 117-. (canceled)18. MARTENSITIC-FERRITIC STAINLESS STEEL , wherein it comprises a martensitic-ferritic microstructure , and a chemical composition in the range of C: from 0.005 to 0.030%; Si: from 0.10 to 0.40%; Mn from 0.20 to 0.80%; P: 0.020% max; S: 0.005% max; Cr: from 13 to 15%; Ni: from 4.0 to 6.0%; Mo: from 2.0 to 4.5%; V: from 0.01 to 0.10%; Nb: from 0.01 to 0.50%; N: from 0.001 to 0.070%; Al: from 0.001 to 0.060%; Ti: from 0.001 to 0.050%; Cu: from 0.01 to 1.50%; O: 0.005% max (in weight percent) , wherein the balance is performed by Fe and unavoidable impurities from the industrial possessing in acceptable levels and having the localized corrosion parameter (LCP) between 3 ...

Flowforming corrosion resistant alloy tubes

Flowforming processes for the production of corrosion resistant alloy tubes are disclosed.

Rolled steel bar for hot forging, hot-forged section material, and common rail and method for producing the same

A rolled steel bar for hot forging consisting, by mass percent, of C: 0.25-0.50%, Si: 0.40-1.0%, Mn: 1.0-1.6%, S: 0.005-0.035%, Al: 0.005-0.050%, V: 0.10-0.30%, and N: 0.005-0.030%, and the balance of Fe and impurities, i.e., P: 0.035% or less and O: 0.0030% or less, wherein Fn1=C+Si/10+Mn/5+5Cr/22+1.65V−5S/7 is 0.90 to 1.20. The predicted maximum width of nonmetallic inclusions at the time when a cumulative distribution function obtained by extreme value statistical processing by taking the width of nonmetallic inclusion in an R 1 /2 part of a longitudinal cross section of the steel bar as W (mm) is 99.99% is 100 mm or narrower. The number density of sulfides each having a circle-equivalent diameter of 0.3 to 1.0 mm observed per unit area of the R 1 /2 part of a transverse cross section of the steel bar is 500 pieces/mm 2 or higher.

AUSTENITIC STAINLESS STEEL HAVING EXCELLENT PIPE-EXPANDABILITY AND AGE CRACKING RESISTANCE

The austenitic stainless steel that does not cause defects such as aging crack or delayed fracture even after the expansion and curling process of 5 steps or more is disclosed. In accordance with an aspect of the present disclosure, an austenitic stainless steel with excellent pipe expanding workability and aging crack resistance includes, in percent (%) by weight of the entire composition, C: 0.01 to 0.04%, Si: 0.1 to 1.0%, Mn: 0.1 to 2.0%, Cr: 16 to 20%, Ni: 6 to 10%, Cu: 0.1 to 2.0%, Mo: 0.2% or less, N: 0.035 to 0.07%, the remainder of iron (Fe) and other inevitable impurities, and the C+N satisfies 0.1% or less, the product of the Md30 (° C.) value and average grain size (μm) satisfies less than −500. 1. An austenitic stainless steel with excellent pipe expanding workability and aging crack resistance comprising , in percent (%) by weight of the entire composition , C: 0.01 to 0.04% , Si: 0.1 to 1.0% , Mn: 0.1 to 2.0% , Cr: 16 to 20% , Ni: 6 to 10% , Cu:2. The austenitic stainless steel according to claim 1 , wherein the C+N satisfies the range of 0.06 to 0.1%.3. The austenitic stainless steel according to claim 1 , wherein the work-hardening exponent n value in the range of true strain 0.3 to 0.4 satisfies the range of 0.45 to 0.5.4. The austenitic stainless steel according to claim 1 , wherein the Md30 value in the above equation (1) is −10° C. or less.5. The austenitic stainless steel according to claim 1 , wherein the average grain size is 45 μm or more.6. The austenitic stainless steel according to claim 1 , wherein the aging crack limited drawing ratio of the stainless steel is 2.97 or more. The present disclosure relates to an austenitic stainless steel with excellent pipe expanding workability, and more specifically, austenitic stainless steel with excellent pipe expanding workability and aging crack resistance, which does not cause defects such as aging crack or delayed fracture even after the expansion and curling process of more than 5 steps.Recently ...

HIGH TENSILE AND HIGH TOUGHNESS STEELS

The present invention deals with alloyed steels having yield strength of at least 862 MPa (125 Ksi) and exhibiting outstanding hardness and toughness behavior, especially under stringent conditions which may be subjected to frost-heave and thaw settlement cycles, namely at subzero temperatures. The invention also relates to a seamless pipe comprising said steel and a method of production of said pipe thereof. 1. A steel for seamless pipe having the following chemical composition consisting of in weight percent:C: from 0.27 to 0.30 wt %,Si: from 0.20 to 0.35 wt %,Mn: from 0.80 to 0.90 wt %,Cr: from 1.30 to 1.45 wt %,Mo: from 0.65 to 0.75 wt %,Ni: from 0.15 to 0.25 wt %,Cu: max 0.25 wt %,Al: from 0.015 to 0.035 wt %,Ti: from 0.024 to 0.038 wt %,N: max 0.012 wt %,V: max 0.05 wt %B: from 0.001 to 0.0025 wt %,Nb: from 0.02 to 0.03 wt %,wherein the balance of said steel being iron and unavoidable impurities from the industrial processing, and having a yield strength (Ys) of at least 862 MPa and an ultimate tensile strength (UTS), wherein a ratio between the yield strength (Ys) and the ultimate tensile strength (UTs) is lower than 0.93.2. The steel according to claim 1 , wherein the chemical composition consisting of in weight percent:C: from 0.27 to 0.30 wt %,Si: from 0.22 to 0.30 wt %,Mn: from 0.80 to 0.85 wt %,Cr: from 1.30 to 1.40 wt %,Mo: from 0.65 to 0.70 wt %,Ni: from 0.15 to 0.20 wt %,Cu: from 0.10 to 0.20 wt %,Al: from 0.017 to 0.030 wt %,Ti: from 0.028 to 0.038 wt %,N: from 0.001 to 0.010 wt %,V: from 0.001 to 0.020 wt %,B: from 0.0010 and 0.0018%,Nb: from 0.020 to 0.025 wt %,wherein the balance of said steel being iron and unavoidable impurities from the industrial processing.3. The steel according to claim 1 , wherein the ratio between the yield strength (Ys) and the ultimate yield strength (UTs) is lower than 0.9.4. The steel according to claim 1 , wherein the yield strength (Ys) is of at least 900 MPa claim 1 , preferably of at least 930 MPa.5. The steel ...

SULPHIDE STRESS CRACKING RESISTANT STEEL, TUBULAR PRODUCT MADE FROM SAID STEEL, PROCESS FOR MANUFACTURING A TUBULAR PRODUCT AND USE THEREOF

The present invention relates to low alloy steels with a high yield strength that present an improved sulphide stress cracking behaviour. The present invention also relates to tubular products, such as tubes or pipes, made from said steel, as well as a process for manufacturing such tubular products. In addition, the present invention concerns use of such tubular products for well drilling and/or for production, extraction and/or transportation of oil and gas. 1. A steel having a chemical composition consisting of , in weight % , relative to the total weight of said chemical composition:0.32≤C<0.46;0.10≤Si≤0.45;0.10≤Mn≤0.50;0.30≤Cr≤1.25;1.10≤Mo≤2.10;0.10≤V≤0.30;0.01≤Nb≤0.10;Fe, andone or more residual elements comprising Cu; and {'br': None, 'β+1.5*α−165≥0'}, 'wherein the chemical composition satisfies formula between C, Si, Mn, Cr, Mo, V, Nb and Cu, the contents of which are expressed in weight %in which,α=−90+274*C−25*Si−64*Mn+22*Cr+17*Mo+268*V−225*Nb+184*Cu, andβ=54+162*C−86*Si−49*Mn−31*Cr+22*Mo+20*V−172*Nb−364*Cu.2. The steel according to claim 1 , having a yield strength greater than or equal to 862 MPa (125 ksi) in standards ASTM A370-17 and ASTM E8/E8M-13a.3. The steel according to either claim 1 , wherein the chemical composition contains in weight % claim 1 , relative to the total weight of said chemical composition: 0.34≤C≤0.44.4. The steel according to claim 1 , wherein the chemical composition contains in weight % claim 1 , relative to the total weight of said chemical composition: 0.20≤Mn≤0.40.5. The steel according to claim 1 , wherein the chemical composition contains in weight % claim 1 , relative to the total weight of said chemical composition: 0.30≤Cr≤1.20.6. The steel according to claim 1 , wherein the chemical composition contains in weight % claim 1 , relative to the total weight of said chemical composition: 1.10 Подробнее

STEEL MATERIAL FOR LINE PIPES, METHOD FOR PRODUCING THE SAME, AND METHOD FOR PRODUCING LINE PIPE

A method for producing a steel material for line pipes including heating a steel having a specific composition to a temperature of 1000° C. to 1200° C.; performing hot rolling such that a cumulative rolling reduction ratio in a non-recrystallization temperature range is 60% or more, a cumulative rolling reduction ratio in a temperature range of (a rolling finish temperature +20° C.) or less is 50% or more, and a rolling finish temperature is the Artransformation point or more and 790° C. or less; subsequently performing accelerated cooling from a temperature of the Artransformation point or more, at a cooling rate of 10° C./s or more, to a cooling stop temperature of 200° C. to 450° C.; and then performing reheating such that the temperature of a surface of the steel plate is 350° C. to 550° C. and the temperature of the center of the steel plate is less than 550° C. 1. A method for producing a steel material for line pipes , the steel material having a tensile strength of 570 MPa or more , a compressive strength of 440 MPa or more , and a thickness of 30 mm or more , the method comprising heating a steel having a composition containing , by mass ,C: 0.030% to 0.10%,Si: 0.01% to 0.30%,Mn: 1.0% to 2.0%,Nb: 0.005% to 0.050%,Ti: 0.005% to 0.025%, andAl: 0.08% or less,the composition further containing one or more elements selected from, by mass,Cu: 0.5% or less,Ni: 1.0% or less,Cr: 1.0% or less,Mo: 0.5% or less, andV: 0.1% or less,{'sub': 3', '3', '3, 'claim-text': [{'br': None, 'i': 'Ceq', '=C+Mn/6+(Cu+Ni)/15+(Cr+Mo+V)/5 \u2003\u2003(1)'}, {'br': None, 'i': 'Pcm', '=C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10 \u2003\u2003(2)'}, {'br': None, 'sub': '3', 'Ar(° C.)=910−310C−80Mn−20Cu−15Cr−55Ni−80Mo \u2003\u2003(3)'}], 'wherein a Ceq value represented by Formula (1) is 0.350 or more, a Pcm value represented by Formula (2) is 0.20 or less, and an Artransformation point represented by Formula (3) is 750° C. or less, with the balance being Fe and inevitable impurities, to a ...

Steel pipe and method for producing steel pipe

The steel pipe according to the present disclosure contains a chemical composition consisting of, in mass %, C: more than 0.50 to 0.65%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0050% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.50%, Mo: 0.25 to 3.00%, Ti: 0.002 to 0.050%, N: 0.0010 to 0.0100% and O: 0.0030% or less, with the balance being Fe and impurities. The steel pipe contains an amount of dissolved C within a range of 0.010 to 0.060 mass %. The tensile yield strength in the axial direction and the circumferential direction is 862 to 1069 MPa, and the yield ratio in the axial direction is 90% or more. The tensile yield strength in the circumferential direction is 30 to 80 MPa higher than the compressive yield strength in the circumferential direction.

METHOD FOR PRODUCING HIGH-STRENGTH STEEL MATERIAL EXCELLENT IN SULFIDE STRESS CRACKING RESISTANCE

A steel has a chemical composition consisting of, by mass percent, C: 0.15-0.65%, Si: 0.05-0.5%, Mn: 0.1-1.5%, Cr: 0.2-1.5%, Mo: 0.1-2.5%, Ti: 0.005-0.50%, Al: 0.001-0.50%, and optionally at least one element selected from Nb: ≦0.4%, V: ≦0.5%, and B: ≦0.01%, Ca: ≦0.005° A, Mg: ≦0.005%, and REM: ≦0.005%, and the balance of Fe and impurities, wherein Ni, P, S, N and O as impurities are Ni: ≦0.1%, P: ≦0.04%, S: ≦0.01%, N: ≦0.01%, and O: ≦0.01%. The steel is hot-worked into a shape and then sequentially subjected to heating the steel to a temperature exceeding the Actransformation point and lower than the Actransformation point and cooling. Then, a step of reheating the steel to a temperature not lower than the Actransformation point and quenching the steel by rapid cooling, and a step of tempering the steel at a temperature not higher than the Actransformation point are performed. 1. A method for producing a high-strength steel material excellent in sulfide stress cracking resistance , wherein a steel that has a chemical composition consisting of , by mass percent , C: 0.15 to 0.65% , Si: 0.05 to 0.5% , Mn: 0.1 to 1.5% , Cr: 0.2 to 1.5% , Mo: 0.1 to 2.5% , Ti: 0.005 to 0.50% , Al: 0.001 to 0.50% , and the balance of Fe and impurities , wherein Ni , P , S , N and O among the impurities are Ni: 0.1% or less , P: 0.04% or less , S: 0.01% or less , N: 0.01% or less , and O: 0.01% or less , and that has been hot-worked into a desired shape is sequentially subjected to the steps of the following [1] to [3]:{'sub': 1', '3, '[1] A step of heating the steel to a temperature exceeding the Actransformation point and lower than the Actransformation point and cooling the steel;'}{'sub': '3', '[2] A step of reheating the steel to a temperature not lower than the Actransformation point and quenching the steel by rapid cooling; and'}{'sub': '1', '[3] A step of tempering the steel at a temperature not higher than the Actransformation point.'}2. A method for producing a high-strength ...

SEAMLESS STEEL PIPE AND METHOD FOR PRODUCING SAME

A seamless steel pipe has a carbon equivalent Ceq of 0.50% to 0.58%, and contains specified carbides containing Mo at a ratio of 50 mass % or more, V, and at least one selected from the group consisting of Ti and Nb, and having a size of 20 nm or more. 17-. (canceled)8. A method for producing a seamless steel pipe comprising: C: 0.02% to 0.10%,', 'Si: 0.05% to 0.5%,', 'Mn: 1.0% to 2.0%,', 'Mo: 0.5% to 1.0%,', 'Cr: 0.1% to 1.0%,', 'Al: 0.01% to 0.10%,', 'P: 0.03% or less,', 'S: 0.005% or less,', 'Ca: 0.0005% to 0.005%,', 'V: 0.010% to 0.040%,', 'N: 0.002% to 0.007%,', 'at least one selected from the group consisting of Ti: 0.008% or less and Nb: 0.02% to 0.05%, and', 'a balance consisting of Fe and impurities and having a carbon equivalent Ceq defined by the following Formula (2) of 0.50% to 0.58%;, 'heating a steel material including, as a chemical composition, by mass %,'}producing a raw pipe by piercing-rolling the heated steel material;producing a seamless steel pipe by rolling the raw pipe;{'sub': 'c3', 'quenching the seamless steel pipe at a quenching temperature of an Apoint or higher; and'} {'br': None, 'i': 'Ceq', '=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15 \u2003\u2003(2)'}, 'tempering the seamless steel pipe after the quenching at a tempering temperature of 660° C. to 700° C.'}here, into each of the symbols of elements in the formula (2), the amount (mass %) of the corresponding element is substituted, and in the case where an element corresponding to the symbol of the element is not contained, “0” is substituted into the corresponding symbol of the element.9. The method for producing a seamless steel pipe according to claim 8 , further comprising{'sub': 'r1', 'acceleratedly cooling the seamless steel pipe at a cooling rate of 100° C./min or higher until a temperature of the seamless steel pipe reaches a temperature of an Apoint or lower between the producing of the seamless steel pipe and the quenching of the seamless steel pipe,'}wherein the acceleratedly-cooled ...

METHOD FOR FACILITATING THERMOMECHANICAL FORMING PROCESS OF AUSTENITE CONTAINING GRADES TO PRODUCE TAILORED STRENGTH STRUCTURAL COMPONENTS

A method to quantitatively determine the amount of deformation induced martensite as a function of temperature and strain in austenitic stainless steels is used to customize the strength and elongation characteristics of certain portions of a formed structural component. Predicting the martensitic volume fraction in a specific part location permits design of particular components with customized strength characteristics that can be consistently repeatably manufactured. 1. A process for preparing a formed part comprising the steps of:a. Identifying at least one pre-determined mechanical property in a region of the formed part;b. Associating a martensite volume fraction level with said pre-determined mechanical property;c. Using a universal strain curve to determine the normalized strain corresponding to the martensite volume fraction; andd. Either selecting a steel to provide the normalized strain or selecting process constraints in a forming process to provide the normalized strain.2. The process of wherein the normalized strain is provided by selecting a particular grade of steel.3. The process of wherein the normalized strain is provided by selecting process constraints in a forming process.4. The process of wherein the process constraints comprise at least one of effective strain or forming temperature.5. The process of wherein the effective strain is provided by a stamping die configuration.6. The process of wherein the steel is an austenitic stainless or carbon steel.7. The process of wherein the steel includes retained austenite.8. The process of wherein the blank is a tube.9. The process of wherein the blank is a sheet.10. The process of wherein the mechanical properties can include strength level.11. A process for preparing a formed part comprising the steps of:a. Providing a blank made of steel to be formed into a formed part, wherein the formed part has at least two regions with differing mechanical properties;b. Identifying the mechanical parameters for ...

STEEL PLATE FOR HIGH-STRENGTH AND HIGH-TOUGHNESS STEEL PIPES AND METHOD FOR PRODUCING STEEL PLATE

A steel plate for high-strength and high-toughness steel pipes has a chemical composition containing, by mass %, C: 0.03% or more and 0.08% or less, Si: more than 0.05% and 0.50% or less, Mn: 1.5% or more and 2.5% or less, P: 0.001% or more and 0.010% or less, S: 0.0030% or less, Al: 0.01% or more and 0.08% or less, Nb: 0.010% or more and 0.080% or less, Ti: 0.005% or more and 0.025% or less, and N: 0.001% or more and 0.006% or less, and further containing, by mass %, at least one selected from Cu: 0.01% or more and 1.00% or less, Ni: 0.01% or more and 1.00% or less, Cr: 0.01% or more and 1.00% or less, Mo: 0.01% or more and 1.00% or less, V: 0.01% or more and 0.10% or less, and B: 0.0005% or more and 0.0030% or less, with the balance being Fe and inevitable impurities. The steel plate has a microstructure in which an area fraction of ferrite at a ½ position of a thickness of the steel plate is 20% or more and 80% or less and deformed ferrite constitutes 50% or more and 100% or less of the ferrite. 1. A steel plate for high-strength and high-toughness steel pipes , the steel plate having a chemical composition containing , by mass % ,C: 0.03% or more and 0.08% or less,Si: more than 0.05% and 0.50% or less,Mn: 1.5% or more and 2.5% or less,P: 0.001% or more and 0.010% or less,S: 0.0030% or less,Al: 0.01% or more and 0.08% or less,Nb: 0.010% or more and 0.080% or less,Ti: 0.005% or more and 0.025% or less, andN: 0.001% or more and 0.006% or less, and further containing, by mass %, at least one selected fromCu: 0.01% or more and 1.00% or less,Ni: 0.01% or more and 1.00% or less,Cr: 0.01% or more and 1.00% or less,Mo: 0.01% or more and 1.00% or less,V: 0.01% or more and 0.10% or less, and wherein the steel plate has a microstructure in which an area fraction of ferrite at a ½ position of a thickness of the steel plate is 20% or more and 80% or less and deformed ferrite constitutes 50% or more and 100% or less of the ferrite, and', {'sub': '−55° C.', 'sup': '−1', 'claim- ...

QUENCHING PROCESSING APPARATUS

The present invention includes: a conveying mechanism () that conveys a workpiece () in the longitudinal direction; a supporting mechanism () that is arranged on the downstream side in the conveyance direction of the workpiece () from the conveying mechanism (); and a heating mechanism () that is arranged on the downstream side in the conveyance direction of the workpiece () from the supporting mechanism () and heats the workpiece (), in which the supporting mechanism () is formed to include support rolls () that abut on an outer surface of the workpiece () and each include a hollow structure () allowing a cooling medium to pass therethrough therein. 1. A quenching processing apparatus that processes a workpiece , the quenching processing apparatus comprising:a conveying mechanism that conveys the workpiece in the longitudinal direction;a supporting mechanism that is arranged on the downstream side in the conveyance direction of the workpiece from the conveying mechanism and supports the workpiece; anda heating mechanism that heats the workpiece, whereinthe supporting mechanism includes rolls that abut on an outer surface of the workpiece and each include a hollow structure allowing a cooling medium to pass therethrough therein, andthe roll is formed by including an outer ring portion that abuts on the outer surface of the workpiece;a shaft that is arranged at an inner side of the outer ring portion, supports the outer ring portion rotatably, and includes the hollow structure therein; anda sliding bearing arranged between the outer ring portion and the shaft.2. The quenching processing apparatus according to claim 1 , further comprising:a holding mechanism that is arranged on the downstream side in the conveyance direction of the workpiece from the heating mechanism and is capable of holding the workpiece and additionally, adding a bending load to the workpiece.3. The quenching processing apparatus according to claim 1 , whereinthe outer ring portion is formed of a ...

METHOD OF MANUFACTURING SUPERIOR 13CR THICKENED DRILLROD

A method for manufacturing a superior 13Cr thickened drillrod comprises the following steps: firstly, thickening the ends of a steel tube with a composition so as to obtain a drillrod with thickened ends, the composition in percentage by weight being: C: 0.01-0.05%, Si≦0.5%, Mn: 0.2-1.0%, Cr: 12-14%, Mo: 1-3%, Ni: 4-6%, and a balance of Fe and inevitable impurities; after heating the tube as a whole to 950-1000° C., air cooling same and tempering same at 600-650° C.; and machining the two thickened ends respectively into an externally threaded drillrod coupler and an internally threaded drillrod coupler; wherein the tube end thickening is an external thickening, including three rounds of heating and three rounds of thickening, with at least one pass of deformation for each round, and the heating temperature being 1150-1200° C. for each round; and the upsetting pressure for the first round of external thickening is 180-220 bars, the upsetting pressure for the second round of external thickening is 180-220 bars, and the upsetting pressure for the third round of external thickening is 140-180 bars. The drillrod according to the present invention can be used not only as a drillrod but also as an oil tube, fulfilling requirements of the exploration operation of a CO-containing gas field of compact sandstone with a high yield. 1. A method for manufacturing a superior 13Cr thickened drillrod according to the present invention , comprising the following steps: firstly thickening the ends of a steel tube with a composition so as to obtain a drillrod with thickened ends , the composition in percentage by weight being: C:0.01-0.05% , Si:≦0.5% , Mn: 0.2-1.0% , Cr: 12-14% , Mo: 1-3% , Ni: 4-6% , and a balance of Fe and inevitable impurities; after heating the tube as a whole to a temperature of 950-1000° C. , air cooling same and finally tempering same at 600-650° C. , with the drillrod tube body and the thickened ends achieving a mechanic feature of 110 ksi; after the heating ...

Steel material for composite pressure vessel liner, steel pipe or tube for composite pressure vessel liner, and method of manufacturing steel pipe or tube for composite pressure vessel liner

Steel material for composite pressure vessel liners that, when used as raw material for manufacturing a composite pressure vessel liner, yields a liner having sufficient strength and a high fatigue limit and enables the manufacture of an inexpensive composite pressure vessel is provided. Steel material for composite pressure vessel liners comprises: a chemical composition containing, in mass %, C: 0.10% to 0.60%, Si: 0.01% to 2.0%, Mn: 0.1% to 5.0%, P: 0.0005% to 0.060%, S: 0.0001% to 0.010%, N: 0.0001% to 0.010%, and Al: 0.01% to 0.06%, with a balance being Fe and incidental impurities; and a metallic microstructure in which a mean grain size of prior austenite grains is 20 μm or less, and a total area ratio of martensite and lower bainite is 90% or more.

Method For Manufacturing Hollow Shafts

The present invention describes a method of manufacturing a near-net shaped hollow shaft useful for high power applications such as gearboxes for wind energy industry. The method involves providing a concast bloom (of a round or rectangular or of any polygonal cross section) or an as-cast round ingot from which a hollow perform is prepared using hollow die punching, followed by process of heat treatment, proof-machining and stress relieving. 1. A method for manufacturing hollow shafts from an input object for use in the gearboxes of wind-energy applications characterised in that said method comprises the steps of optimisation of the near net shape through forging followed by proof machining and stress relieving , said input object is a concast bloom or an ingot is in round or polygonal in cross section , wherein said step of optimising the near net shape comprises the steps of:a. heating said bloom or ingot in a furnaceb. first upsetting said bloom or ingot to an intermediate heightc. drawing the upset bloom or ingot to an intermediate diameterd. providing booster heating to the drawn bloom or ingote. second upsetting the booster-heated bloom or ingot in a hollow die to the final height of the preformf. punching the second upset bloom or ingot in a hollow dieg. Providing heat treatment to the punched bloom or ingot to carry out normalising, hardening and double tempering so as to produce a near net shaped hollow shaft.2. A method for manufacturing hollow shafts as claimed in wherein in the case said concast bloom or ingot is in substantially rectangular in cross section claim 1 , the said step of optimising the near net shape comprises the steps of:a. heating said bloom or ingot in a furnaceb. first upsetting the heated ingot or bloom to an intermediate heightc. drawing the first upset bloom or ingot to an intermediate diameterd. providing booster heating to the drawn bloom or ingote. second upsetting in the booster-heated bloom or ingot in a hollow die to the final ...

LOW ALLOY HIGH STRENGTH SEAMLESS STEEL PIPE FOR OIL COUNTRY TUBULAR GOODS

The steel pipe of the present invention is a low alloy high strength seamless steel pipe for oil country tubular goods including a composition containing, in terms of mass %, C: 0.23 to 0.27%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 0.5 to 1.0%, Nb: 0.02 to 0.05%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a value of a ratio of the Ti content to the N content (Ti/N) of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve; of 1.02 or less and a yield strength of 655 MPa or more. 1. A low alloy high strength seamless steel pipe for oil country tubular goods comprising a composition containing , in terms of mass % ,C: 0.23 to 0.27%,Si: 0.01 to 0.35%,Mn: 0.45 to 0.70%,P: 0.010% or less,S: 0.001% or less,O: 0.0015% or less,Al: 0.015 to 0.080%,Cu: 0.02 to 0.09%,Cr: 0.8 to 1.5%,Mo: 0.5 to 1.0%,Nb: 0.02 to 0.05%,B: 0.0015 to 0.0030%,Ti: 0.005 to 0.020%, andN: 0.005% or less,and having a value of a ratio of the Ti content to the N content (Ti/N) of 3.0 to 4.0,with the balance being Fe and inevitable impurities,{'sub': 0.7', '0.4, 'the steel pipe having a value (σ/σ), as a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve, of 1.02 or less and a yield strength of 655 MPa or more.'}2. The low alloy high strength seamless steel pipe for oil country tubular goods according to claim 1 , which further contains claim 1 , in addition to the composition claim 1 , one or more selected from claim 1 , in terms of mass % claim 1 ,V: 0.01 to 0.06%,W: 0.1 to 0.2%, andZr: 0.005 to 0.03%.3. The low alloy high strength seamless steel pipe for oil country tubular goods according to claim 1 , which further contains claim 1 , in addition to the composition claim 1 , in terms ...

Low alloy high strength seamless steel pipe for oil country tubular goods

A low alloy high strength seamless steel pipe for oil country tubular goods is provided including a composition containing, in terms of mass %, C: 0.25 to 0.31%, Si: 0.01 to 0.35%, Mn: 0.45 to 0.70%, P: 0.010% or less, S: 0.001% or less, 0: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 1.1 to 1.6%, V: 0.01 to 0.06%, Nb: 0.005 to 0.015%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having a ratio of the Ti content to the N content of 3.0 to 4.0, with the balance being Fe and inevitable impurities, the steel pipe having a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve of 1.02 or less and a yield strength of 861 MPa or more.

STEEL MATERIAL AND OIL-WELL STEEL PIPE

A steel material for oil country tubular goods that has a high strength and excellent SSC resistance is provided. The steel material according to this invention contains, in mass %, C: more than 0.45 to 0.65%, Si: 0.10 to 1.0%, Mn: 0.1 to 1.0%, P: 0.050% or less, S: 0.010% or less, Al: 0.01 to 0.1%, N: 0.01% or less, Cr: 0.1 to 2.5%, Mo: 0.25 to 5.0%, and Co: 0.05 to 5.0%, and satisfies expressions (1) and (2), and contains 90% or more of tempered martensite by volume ratio: 1. A steel material comprising a chemical composition consisting of , in mass % ,C: more than 0.45 to 0.65%,Si: 0.10 to 1.0%,Mn: 0.1 to 1.0%,P: 0.050% or less,S: 0.010% or less,Al: 0.01 to 0.1%,N: 0.01% or less,Cr: 0.1 to 2.5%,Mo: 0.25 to 5.0%,Co: 0.05 to 5.0%,Cu: 0 to 0.50%,Ni: 0 to 0.50%,Ti: 0 to 0.030%,Nb: 0 to 0.15%,V: 0 to 0.5%,B: 0 to 0.003%,Ca: 0 to 0.004%,Mg: 0 to 0.004%,Zr: 0 to 0.004%, andrare earth metal: 0 to 0.004%,with a balance being Fe and impurities, and satisfying expressions (1) and (2), [{'br': None, 'C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15−Co/6+α≥0.70\u2003\u2003(1)'}, {'br': None, '(3C+Mo+3Co)/(3Mn+Cr)≥1.0\u2003\u2003(2)'}, {'br': None, 'Effective B=B−11(N−Ti/3.4)/14\u2003\u2003(3)'}], 'wherein the microstructure comprises, by volume ratio, 90% or more of tempered martensitewhere, α in expression (1) is 0.250 when effective B (mass %) defined by expression (3) is 0.0003% or more, and is 0 when the effective B is less than 0.0003%, where a content (mass %) of a corresponding element is substituted for each symbol of an element in expression (1) to expression (3).2. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from a group consisting of:Cu: 0.02 to 0.50%, andNi: 0.02 to 0.50%.3. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from a group consisting of:Ti: 0.003 to 0.030%,Nb: 0.003 to 0.15%, andV: 0.005 to 0.5%.46-. (canceled)7. The ...

STEEL COMPOSITION IN ACCORDANCE WITH API 5L PSL-2 SPECIFICATION FOR X-65 GRADE HAVING ENHANCED HYDROGEN INDUCED CRACKING (HIC) RESISTANCE, AND METHOD OF MANUFACTURING THE STEEL THEREOF

The present disclosure relates to designing of steel composition for line pipe steel to be used for sour environment. The developed steel of the present disclosure exhibits enhanced tensile properties in accordance with API 5L PSL-2 specification for X-65 grade steel, along with superior hydrogen induced cracking resistance with crack length ratio (CLR) of less than 10%, crack thickness ratio (CTR) of less than 5%, crack sensitivity ratio (CSR) of less than 2%. The developed steel is designed such that it is readily hot/cold formed and welded to form linepipe tubes to be used for the transportation of natural gas or crude oil, especially of sour grade. The present disclosure also provide a method of manufacturing the said steel having the composition of the present disclosure. 1. A steel composition comprising Carbon (C) at a concentration ranging from about 0.02% to about 0.06%; Manganese (Mn) at a concentration ranging from about 0.7% to about 1.3%; Niobium (Nb) at a concentration ranging from about 0.06% to about 0.10%; Titanium (Ti) at a concentration ranging from about 0.015% to about 0.025%; Aluminium (Al) at a concentration ranging from about 0.03% to about 0.10%; Silicon (Si) at a concentration ranging from about 0.1% to about 0.5%; Nitrogen (N) at a concentration ranging from about 0.0001% to about 0.0060%; Sulphur (S) at a concentration ranging from about 0.0001% to about 0.0020%; and Phosphorus (P) at a concentration ranging from about 0.0001% to about 0.015% ,wherein said steel composition exhibits crack length ratio (CLR) of less than 10%, crack thickness ratio (CTR) of less than 5%, crack sensitivity ratio (CSR) of less than 2%, and ferrite potential of less than 0.85 or more than 1.05.2. The steel composition as claimed in claim 1 , wherein the steel having the said composition is non-peritectic claim 1 , conforms to API 5L PSL-2 X65 specification and provides high resistance to hydrogen induced cracking (HIC).3. The steel composition as claimed in ...

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

A preferable aspect of the present invention provides a hot-rolled steel sheet with excellent low-temperature toughness, a steel pipe using the same, and a manufacturing method therefor, wherein the hot-rolled steel sheet contains, by weight, 0.35-0.65% C, 0.01-0.4% Si, 13-26% Mn, 0.01-0.3% Ti, 0.01% or less B, 4% or less Al, 1-6% Cr, 0.05% or less P, 0.02% or less S, 0.01% or less N, 0.01-2% Cu, 0.001-0.015% Nb, and the balance Fe and other unavoidable impurities, the alloy elements satisfying the following relational formulas—[Relational formula 1] 70<[10*(C/12)+(Mn/55)+(Al/27)]*100<95 and [Relational formula 2] 4<100*(Cr/52+100*(Nb/93))<9; wherein a microstructure comprises, by area fraction, 97% or more (including 100%) of austenite and 3% or less (including 0%) of a carbide, the crystal grain size of the austenite being 18-30 μm or less; and wherein the size of the carbide is 0.5 μm or less. 1. A hot-rolled steel plate having excellent low-temperature toughness , comprising: [{'br': None, '70<[10*(C/12)+(Mn/55)+(Al/27)]*100<95\u2003\u2003[Relational Formula 1]'}, {'br': None, '4<100*(Cr/52+100*(Nb/93))<9,\u2003\u2003[Relational Formula 2]'}], 'by weight %, 0.35% to 0.65% of C, 0.01 to 0.4% of Si, 13% to 26% of Mn, 0.01% to 0.3% of Ti, 0.01% or less (excluding 0%) of B, 4% or less (excluding 0%) of Al, 1% to 6% of Cr, 0.05% or less (including 0%) of P, 0.02% or less (including 0%) of S, 0.01% or less (excluding 0%) of N, 0.01% to 2% of Cu, 0.001% to 0.015% of Nb, and a remainder of Fe and other inevitable impurities, the alloy elements satisfying the following relational formulawherein a microstructure comprises, by area fraction, 97% or more (including 100%) of austenite and 3% or less (including 0%) of a carbide, the austenite having a grain size of 18 μm to 30 μm and the carbide having a size of 0.5 μm or less.2. The hot-rolled steel plate having excellent low-temperature toughness of claim 1 , wherein the hot-rolled steel plate has inclusions that the number ...

HIGH PERFORMANCE MATERIAL FOR COILED TUBING APPLICATIONS AND THE METHOD OF PRODUCING THE SAME

Embodiments of the present disclosure are directed to coiled steel tubes and methods of manufacturing coiled steel tubes. In some embodiments, the final microstructures of the coiled steel tubes across all base metal regions, weld joints, and heat affected zones can be homogeneous. Further, the final microstructure of the coiled steel tube can be a mixture of tempered martensite and bainite. 122. . (canceled)23. A coiled steel tube having improved yield strength and fatigue life at weld joints of the coiled steel tube , the coiled steel tube comprising:a plurality of strips welded together end to end by a bias weld to form a plurality of bias welded strips and formed into a coiled steel tube, each of the plurality of bias welded strips having base metal regions, bias weld joints, and heat affected zones surrounding the bias weld joints, each of the plurality of bias welded strips having a yield strength greater than about 80ksi; {'br': None, 'where CE=%C+((%Mn+%Si)/6)+((%Cr+%Mo+%V)/5)+((%Cu+%Ni)/15);'}, 'an equivalent carbon content (CE) in the range of 0.237 to 0.733;'}wherein the coiled steel tube has a final microstructure formed from a full body heat treatment applied to the coiled steel tube;wherein the final microstructure comprises a mixture of tempered martensite and bainite;wherein the final microstructure of the coiled steel tube comprises more than 90 volume % tempered martensite in the base metal regions, the bias weld joints, and the heat affected zones;wherein the final microstructure across all base metal regions, bias weld joints, and heat affected zones is homogeneous; andwherein the final microstructure comprises a uniform distribution of fine carbides across the base metal regions, the bias weld joints, and the heat affected zones.24. The coiled steel tube of claim 23 , wherein the tube has a minimum yield strength of 125 ksi.25. The coiled steel tube of claim 23 , wherein the tube has a minimum yield strength of 140 ksi.26. The coiled steel tube ...

HIGH STRENGTH STEEL PLATE HAVING LOW YIELD RATIO EXCELLENT IN TERMS OF STRAIN AGEING RESISTANCE, METHOD OF MANUFACTURING THE SAME AND HIGH STRENGTH WELDED STEEL PIPE MADE OF THE SAME

A steel plate has a chemical composition containing, by mass %, C: 0.03% or more and 0.08% or less, Si: 0.01% or more and 1.0% or less, Mn: 1.2% or more and 3.0% or less, P: 0.015% or less, S: 0.005% or less, Al: 0.08% or less, Nb: 0.005% or more and 0.07% or less, Ti: 0.005% or more and 0.025% or less, N: 0.010% or less, O: 0.005% or less and the balance being Fe and inevitable impurities, a metallographic structure including a bainite phase and island martensite, and a polygonal ferrite in surface portions within 5 mm from the upper and lower surfaces, wherein the area fraction of the island martensite is 3% to 15%, the equivalent circle diameter of the island martensite is 3.0 μm or less, the area fraction of the polygonal ferrite in the surface portions is 10% to less than 80%. 1. A high strength steel plate having a low yield ratio , the steel plate having a chemical composition containing , by mass % , C: 0.03% or more and 0.08% or less , Si: 0.01% or more and 1.0% or less , Mn: 1.2% or more and 3.0% or less , P: 0.015% or less , S: 0.005% or less , Al: 0.08% or less , Nb: 0.005% or more and 0.07% or less , Ti: 0.005% or more and 0.025% or less , N: 0.010% or less , O: 0.005% or less and the balance being Fe and inevitable impurities , a metallographic structure including a bainite phase and island martensite , and further including a polygonal ferrite phase in surface portions within 5 mm from the upper and lower surfaces , wherein an area fraction of island martensite is 3% or more and 15% or less , wherein an equivalent circle diameter of the island martensite is 3.0 μm or less , wherein the area fraction of the polygonal ferrite phase in the surface portions is 10% or more and less than 80% , and wherein the remainder of the metallographic structure consists of a bainite phase , a hardness variation in a thickness direction of ΔHV30 or less in terms of Vickers hardness , a hardness variation in a width direction of ΔHV30 or less in terms of Vickers ...

STEEL SHEET FOR CANS AND METHOD OF PRODUCING SAME

Provided is a steel sheet for cans. A steel sheet for cans comprises: a chemical composition containing, in mass %, C: 0.010% or more and 0.130% or less, Si: 0.04% or less, Mn: 0.10% or more and 1.00% or less, P: 0.007% or more and 0.100% or less, S: 0.0005% or more and 0.0090% or less, Al: 0.001% or more and 0.100% or less, N: 0.0050% or less, Ti: 0.0050% or more and 0.1000% or less, and Cr: 0.08% or less, and satisfying a relationship 0.005≤(Ti*/48)/(C/12)≤0.700 where Ti*=Ti−1.5S, with a balance consisting of Fe and inevitable impurities; a microstructure in which a proportion of cementite in ferrite grains is 10% or less; and an upper yield strength of 550 MPa or more. 1. A steel sheet for cans , comprising:a chemical composition containing, in mass %, C: 0.010% or more and 0.130% or less, Si: 0.04% or less, Mn: 0.10% or more and 1.00% or less, P: 0.007% or more and 0.100% or less, S: 0.0005% or more and 0.0090% or less, Al: 0.001% or more and 0.100% or less, N: 0.0050% or less, Ti: 0.0050% or more and 0.1000% or less, and Cr: 0.08% or less, and satisfying a relationship 0.005≤(Ti*/48)/(C/12)≤0.700 where Ti*=Ti−1.5S, with a balance consisting of Fe and inevitable impurities;a microstructure in which a proportion of cementite in ferrite grains is 10% or less; andan upper yield strength of 550 MPa or more.2. The steel sheet for cans according to claim 1 , wherein the chemical composition further contains claim 1 , in mass % claim 1 , one or more selected from Nb: 0.0050% or more and 0.0500% or less claim 1 , Mo: 0.0050% or more and 0.0500% or less claim 1 , and B: 0.0020% or more and 0.0100% or less.3. A method of producing a steel sheet for cans claim 1 , the method comprising:performing a hot rolling process of heating a steel slab at 1200° C. or more, the steel slab having a chemical composition containing, in mass %, C: 0.010% or more and 0.130% or less, Si: 0.04% or less, Mn: 0.10% or more and 1.00% or less, P: 0.007% or more and 0.100% or less, S: 0.0005% or ...

Steel structure for hydrogen gas, mehtod for producing hydrogen storage tank, and method for producing hydrogen line pipe (as amended)

Provided is a steel structure for hydrogen gas such as a hydrogen storage tank or a hydrogen line pipe which achieves a lower fatigue crack propagation rate in a high-pressure hydrogen atmosphere than steels used in the related art and has high hydrogen embrittlement resistance. The steel structure for hydrogen gas, which has high hydrogen embrittlement resistance in high-pressure hydrogen gas, has a steel microstructure including any one of 10% to 95% of bainite on an area-ratio basis, 10% to 95% of martensite on an area-ratio basis, and 10% to 95% of pearlite on an area-ratio basis, with the balance being substantially ferrite.

LOW ALLOY HIGH STRENGTH THICK-WALLED SEAMLESS STEEL PIPE FOR OIL COUNTRY TUBULAR GOODS

A low alloy high strength thick-walled seamless steel pipe for oil country tubular goods is provided having a wall thickness of 40 mm or more and a yield strength of 758 MPa or more, the steel pipe including a composition containing, in terms of mass %, C: 0.25 to 0.31%, Si: 0.01 to 0.35%, Mn: 0.55 to 0.70%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.040%, Cu: 0.02 to 0.09%, Cr: 0.8 to 1.5%, Mo: 0.9 to 1.6%, V: 0.04 to 0.10%, Nb: 0.005 to 0.05%, B: 0.0015 to 0.0030%, Ti: 0.005 to 0.020%, and N: 0.005% or less, and having Ti/N of 3.0 to 4.0, with the balance being Fe and inevitable impurities, wherein a cumulative frequency rate at a measurement point at which a Mo segregation degree by a predetermined expression is 1.5 or more is 1% or less. 1. A low alloy high strength thick-walled seamless steel pipe for oil country tubular goods having a wall thickness of 40 mm or more and a yield strength of 758 MPa or more , the steel pipe comprising a composition containing , in terms of mass % ,C: 0.25 to 0.31%,Si: 0.01 to 0.35%,Mn: 0.55 to 0.70%,P: 0.010% or less,S: 0.001% or less,O: 0.0015% or less,Al: 0.015 to 0.040%,Cu: 0.02 to 0.09%,Cr: 0.8 to 1.5%,Mo: 0.9 to 1.6%,V: 0.04 to 0.10%,Nb: 0.005 to 0.05%,B: 0.0015 to 0.0030%,Ti: 0.005 to 0.020%, andN: 0.005% or less,and having a value of a ratio of the Ti content to the N content (Ti/N) of 3.0 to 4.0,with the balance being Fe and inevitable impurities,wherein a cumulative frequency rate is 1% or less in view of measurement points at which a Mo segregation degree is 1.5 or more which is measured in an overall thickness of a longitudinal orthogonal cross section of the pipe, as defined by the following expression (A); and{'sub': 0.7', '0.4, 'claim-text': {'br': None, 'Mo segregation degree=(EPMA Mo value)/(EPMA Mo ave.) \u2003\u2003(A)'}, 'the steel pipe has a value (σ/σ), as a ratio of a stress at a strain of 0.7% to a stress at a strain of 0.4% in a stress-strain curve, of 1.02 or lesswhereinthe ...

Hollow Forging Process for Main Shaft of Large Wind Turbine Generator

A hollow forging process for main shaft of large wind turbine generator, wherein, comprising the following steps as: the first step of cutting off the dead head and the bottom of an ingot; the second step of upsetting and punching a hole; the third step of drawing-out; and the fourth step of local upsetting, drawing-out and shaping-up. In the fourth step, the forged piece is shaped up by local upsetting and drawing-out through a turnplate. The hollow forging process for main shaft created by the invention can save the costs for enterprise to purchase large equipment and makes it possible to forge the main shaft of large wind turbine generator with a free forging oil press with a smaller size. 1. A hollow forging process for main shaft of large wind turbine generator , comprising the following steps:a first step of cutting off the dead head and the bottom of an ingot;a second step of upsetting and punching a hole;a third step of drawing-out; anda fourth step of local upsetting, drawing-out and shaping-up.2. The hollow forging process for main shaft of large wind turbine generator according to claim 1 , wherein claim 1 , in the fourth step claim 1 , the forged piece is shaped up by local upsetting and drawing-out through a turnplate; the turnplate comprises a circular turnplate base and a turnplate body connected to the turnplate base; a circular hole that matches the shape of the lower end of the main shaft to be processed is arranged on the turnplate body; a hole with a certain taper is arranged in the middle of the turnplate base claim 1 , which may ensure both excircle and inner hole of the main shaft will not result in eccentricity in combination with a core rod of the same taper.3. The hollow forging process for main shaft of large wind turbine generator according to claim 2 , wherein claim 2 , the overall core rod is a conic cylinder; the head of the core rod is cylindrical; the fillet radius of the end of the core rod is 30-50 mm and the taper of the core rod ...

ROLLED STEEL BAR FOR HOT FORGING, HOT-FORGED SECTION MATERIAL, AND COMMON RAIL AND METHOD FOR PRODUCING THE SAME

A rolled steel bar for hot forging consisting, by mass percent, of C: 0.25-0.50%, Si: 0.40-1.0%, Mn: 1.0-1.6%, S: 0.005-0.035%, Al: 0.005-0.050%, V: 0.10-0.30%, and N: 0.005-0.030%, and the balance of Fe and impurities, i.e., P: 0.035% or less and O: 0.0030% or less, wherein Fn1=C+Si/10+Mn/5+5Cr/22+1.65V−5S/7 is 0.90 to 1.20. The predicted maximum width of nonmetallic inclusions at the time when a cumulative distribution function obtained by extreme value statistical processing by taking the width of nonmetallic inclusion in an R/2 part of a longitudinal cross section of the steel bar as W (mm) is 99.99% is 100 mm or narrower. The number density of sulfides each having a circle-equivalent diameter of 0.3 to 1.0 mm observed per unit area of the R/2 part of a transverse cross section of the steel bar is 500 pieces/mmor higher. 36-. (canceled) The present invention relates to a rolled steel bar for hot forging, a hot-forged section material, a common rail, and a method for producing the common rail. More particularly, it relates to a rolled steel bar for hot forging suitable as a starting material for a common rail used for a diesel engine fuel injection system, a hot-forged section material produced by forming the rolled steel bar, the common rail, and a method for producing the common rail.With environmental problems in the background, a need for improving fuel economy has increased. For parts for mechanical structures used for motor vehicles, industrial machines, and the like, the increase in strength of part has been desired in order to reduce the size thereof.In recent years, the regulation of exhaust gas for motor vehicles tends to be increasingly stricter. For a diesel engine fuel injection system, the combustion efficiency of engine can be enhanced by increasing the injection pressure of fuel. Accordingly, the injection pressure of fuel injected into a diesel engine has been raised. A common rail is a hollow shaped part that is used for the diesel engine fuel ...

HOT-ROLLED STEEL SHEET HAVING EXCELLENT IMPACT RESISTANCE, STEEL PIPE, MEMBER, AND MANUFACTURING METHODS THEREFOR

A preferable aspect of the present invention provides: a hot-rolled steel sheet containing, by weight, 0.35-0.55% of C, 0.7-1.5% of Mn, 0.3% or less of Si, 0.03% or less of P, 0.004% or less of S, 0.04% or less of Al, 0.3% or less (excluding 0%) of Cr, 0.3% or less of Mo, one or two of 0.1-1.0% of Ni and 0.1-1.0% of Cu, 0.4% or more of Cu+Ni, 0.006% or less of N, and the balance Fe and other impurities, the alloy elements satisfying relational formulas 1 to 3 below, wherein a microstructure of the hot-rolled steel sheet comprises, by volume, 10% or more of ferrite and 90% or less of pearlite; a steel pipe and a member each using the same; and manufacturing methods therefore. [Relational formula 1] (Mn/Si)≥3 (weight ratio) [Relational formula 2] (Ni+Cu)/(C+Mn)≥0.2 (weight ratio) [Relational formula 3] (Ni/Si)≥(weight ratio). 1. A hot-rolled steel sheet having excellent impact resistance , comprising: [{'br': None, '(Mn/Si)≥3 (a weight ratio)\u2003\u2003[Relational Formula 1]'}, {'br': None, '(Ni+Cu)/(C+Mn)≥0.2 (a weight ratio)\u2003\u2003[Relational Formula 2]'}, {'br': None, '(Ni/Si)≥1 (a weight ratio)\u2003\u2003[Relational Formula 3]'}], 'by weight %, 0.35-0.55% of C, 0.7-1.5% of Mn, 0.3% or less (excluding 0%) of Si, 0.03% or less (including 0%) of P, 0.004% or less (including 0%) of S, 0.04% or less (excluding 0%) of Al, 0.3% or less (excluding 0%) of Cr, 0.3% or less (excluding 0%) of Mo, one or two of 0.1-1.0% of Ni and 0.1-1.0% of Cu, 0.4% or more of Cu+Ni, 0.006% or less (excluding 0%) of N, and a balance of Fe and other impurities, the alloy elements satisfying relational formulae 1-3 as below, where a microstructure includes, by volume %, 10-30% of ferrite and 70-90% of pearlite.'}2. The hot-rolled steel sheet of claim 1 , further comprising:one or two or more selected from a group consisting of 0.04% or less (excluding 0%) of Ti, 0.005% or less (excluding 0%) of B and 0.03% or less (excluding 0%) of Sb.3. The hot-rolled steel sheet of claim 1 , wherein ...

PRODUCTION METHOD AND PRODUCTION FACILITY OF METAL PIPE

A production method of a metal pipe which can suppress quenching defects is provided. In the production method of a metal pipe according an embodiment of the present invention bend of the metal pipe is straightened by a straightening machine . Next, both pipe end portions of the metal pipe whose bend has been straightened are cut off by a pipe cutting apparatus . Next, a plurality of the metal pipes whose both pipe end portions have been cut off are aligned in the axial direction thereof to be conveyed to a quenching apparatus , and the metal pipes are quenched by being cooled after being heated by induction heating. 1. A production method of a metal pipe , comprising the steps of:straightening bend of the metal pipe by a straightening machine;cutting off both pipe end portions of the metal pipe whose bend has been straightened; andconveying a plurality of the metal pipes whose both pipe end portions have been cut off, to a quenching apparatus, and quenching the metal pipes by cooling after heating by induction heating the metal pipes in the quenching apparatus.2. The production method according to claim 1 , whereinthe quenching apparatus comprises:an induction heating coil disposed at an entrance side of the quenching apparatus; anda cooling apparatus cooling the metal pipe by using a coolant, the cooling apparatus being disposed at an exit side of the quenching apparatus, whereinin the step of quenching, metal pipes aligned fore and aft are conveyed with pipe ends thereof being abutted to each other in the quenching apparatus.3. The production method according to claim 1 , whereina production facility used for the production method comprises:the straightening machine;the quenching apparatus;a conveyor conveying the metal pipe whose bend has been straightened toward the quenching apparatus, the conveyor being disposed between the straightening machine and the quenching apparatus; anda pipe cutting apparatus cutting off both pipe end portions of the metal pipe whose ...

STEEL MATERIAL AND OIL-WELL STEEL PIPE

The steel material according to this invention contains, in mass %, C: 0.15 to 0.45%, Si: 0.10 to 1.0%, Mn: 0.10 to less than 0.90%, P: 0.05% or less, S: 0.01% or less, Al: 0.01 to 0.1%, N: 0.01% or less, Cr: 0.1 to 2.5%, Mo: 0.35 to 3.0%, and Co: 0.50 to 3.0%, and satisfies expressions (1) and (2), and contains 90% or more of tempered martensite by volume ratio: 1. A steel material comprising a chemical composition consisting of , in mass % ,C: 0.15 to 0.45%,Si: 0.10 to 1.0%,Mn: 0.10 to less than 0.90%,P: 0.05% or less,S: 0.01% or less,Al: 0.01 to 0.1%,N: 0.010% or less,Cr: 0.1 to 2.5%,Mo: 0.35 to 3.0%,Co: 0.50 to 3.0%,Cu: 0 to 0.5%,Ni: 0 to 0.5%,Ti: 0 to 0.03%,Nb: 0 to 0.15%,V: 0 to 0.5%,B: 0 to 0.003%,Ca: 0 to 0.004%,Mg: 0 to 0.004%,Zr: 0 to 0.004%, andrare earth metal: 0 to 0.004%,with a balance being Fe and impurities, and satisfying expressions (1) and (2), [{'br': None, 'C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15−Co/6+α≥0.50 \u2003\u2003(1)'}, {'br': None, '(3C+Mo+3Co)/(3Mn+Cr)≥1.0 \u2003\u2003(2)'}, {'br': None, 'Effective B=B−11(N−Ti/3.4)/14 \u2003\u2003(3)'}], 'wherein the microstructure comprises, by volume ratio, 90% or more of tempered martensitewhere, α in expression (1) is 0.250 when effective B (mass %) defined by expression (3) is 0.0003% or more, and is 0 when the effective B is less than 0.0003%, where a,4 content (mass %) of a corresponding element is substituted for each symbol of an element in expression (1) to expression (3).2. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from a group consisting of:Cu: 0.02 to 0.5%, andNi: 0.02 to 0.5%.3. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from a group consisting of:Ti: 0.003 to 0.03%,Nb: 0.003 to 0.15%, andV: 0.005 to 0.5%.46-. (canceled)7. The steel material according to claim 2 , wherein the chemical composition contains one or more types of element selected ...

METHOD OF PRODUCING A TUBE OF A DUPLEX STAINLESS STEEL

The present disclosure relates to a method of producing a tube of a duplex stainless steel, in particular a duplex stainless steel suitable for use in fuel injection systems for injection of fuel into the combustion chamber of a combustion engine. 2. The method according to claim 1 , wherein said temperature range is of from 970° C.-1040° C.3. The method according to claim 1 , wherein said temperature range is of from 1000° C.-1040° C.4. The method according to claim 1 , wherein said annealing step comprises subjected said tube to said temperature for a time period of from 0.5 to 5 minutes.5. The method according to claim 1 , wherein said inert gas is argon or helium or a mixture thereof.6. The method according to claim 1 , wherein the content of nitrogen gas in said gas mixture is equal to or less than 4 vol %.7. The method according to claim 1 , wherein the content of nitrogen gas in said gas mixture is equal to or above 1.5 vol %.8. The method according to claim 1 , wherein step e) comprises subjecting the tube to said hot extrusion at a temperature in the range of from 1100° C. to 1200° C. and a cross-sectional area reduction in the range of from 92-98%.9. The method according to claim 1 , wherein step f) comprises subjecting claim 1 , without pre-heating claim 1 , the tube to cold deformation.10. The method according to claim 1 , wherein step f) comprises subjecting the tube to a cross sectional area reduction in the range of from 50-95%.11. The method according to claim 1 , wherein the cold deformation is pilgering.13. The method according to claim 12 , wherein Q is in the range of from 0.9-1.1.15. The method according to claim 1 , wherein the tube is a tube arranged for conduction of a fuel in a fuel injection system for injecting fuel into the combustion chamber of a combustion engine. The present disclosure relates to a method of producing a tube of a duplex stainless steel, in particular a duplex stainless steel suitable for use in fuel injection systems ...

HIGH-STRENGTH STEEL, METHOD FOR MANUFACTURING HIGH-STRENGTH STEEL, STEEL PIPE, AND METHOD FOR MANUFACTURING STEEL PIPE

A high-strength steel having a specified chemical composition, wherein parameter Pis 0.050% or more, the relationship (TS−TS)/TS≦0.050 is satisfied, wherein TS is defined as tensile strength determined at a temperature of 350° C. after aging has been performed under the condition of a Larson-Miller Parameter (LMP) of 15700, and wherein TSis defined as tensile strength determined at a temperature of 350° C. before the aging is performed, and having a toughness represented by a vEof 100 J or more in a weld heat-affected zone, which is formed when welding is performed. 3. The high-strength steel according to claim 1 , the chemical composition of the high-strength steel further contains claim 1 , by mass % claim 1 , one claim 1 , two claim 1 , or more of:Cu: 0.50% or less, Ni: 0.50% or less, Cr: 0.50% or less, and Ca: 0.0005% to 0.0040%, anda bainite phase fraction of 70% or more.41. A steel pipe composed of the high-strength steel according to cliam .5. A method for manufacturing the high-strength steel according to claim 1 , the method comprising:a heating process wherein a steel raw material is heated to a temperature of 1050° C. to 1200° C.;a hot rolling process wherein the steel raw material, which has been heated in the heating process, is hot-rolled under the conditions of an accumulated rolling reduction ratio in a temperature range of 900° C. or lower of 50% or more and a rolling finish temperature of 850° C. or lower;an accelerated cooling process in which wherein the hot-rolled steel plate, which has been obtained in the hot rolling process, is subjected to accelerated cooling under the conditions of a cooling rate of 5° C./s or more and a cooling stop temperature of 250° C. to 550° C.; anda reheating process wherein the hot-rolled steel plate is reheated, immediately after the accelerated cooling has been finished, under the conditions of a heating rate of 0.5° C./s or more and an end-point temperature of 550° C. to 700° C.6. A method for manufacturing a ...

Method of Manufacturing Two Tubes Simultaneously and Machine for Use Therein

A method is used to manufacture a tube having a hollow interior for housing an axle shaft. The tube is formed in a single machine having a fixed base and a single press structure movable toward the fixed base. The single machine includes first and second die assemblies coupled to the fixed base and first and second mandrels coupled to the single press structure. The method includes the steps of placing a billet into the first die assembly, pressing the billet into the first die assembly with the first mandrel to producing a pre-formed billet, and moving the pre-formed billet from the first die assembly to the second die assembly. THE method further includes the steps of pressing the pre-formed billet into the second die assembly with the second mandrel to elongate the pre-formed billet and form a hollow interior therein to produce an extruded tube. 141-. (canceled)42. A method of manufacturing a tube having a hollow interior for housing an axle shaft , which transmits rotational motion from a prime mover to a wheel of a vehicle , with the tube formed in at least a first machine and a second machine each having a fixed base and a press structure movable toward the fixed base , a first die assembly coupled to the fixed base of the first machine , a second die assembly coupled to the fixed base of the first machine and further defined as an initial stage second die assembly and a later stage second die assembly , a first mandrel coupled to the press structure of the first machine , a second mandrel coupled to the press structure of the first machine and spaced from the first mandrel further defined as an initial stage second mandrel and a later stage second mandrel , a third die assembly coupled to the fixed base of the second machine , and a third mandrel coupled to the press structure of the second machine , said method comprising the steps of:placing a billet into a cavity of the first die assembly;pressing the billet into the cavity of the first die assembly with ...

SEAMLESS STEEL PIPE FOR LINE PIPE AND METHOD FOR PRODUCING THE SAME

A seamless steel pipe for line pipe has a chemical composition consisting, by mass percent, of C: 0.03-0.15%, Si: ≦0.50%, Mn: 1.0-2.0%, P: ≦0.050%, S: ≦0.005%, Cr: 0.1-1.0%, Al: 0.001-0.10%, N: ≦0.01%, Ni: 0.05-2.0%, B: 0.0003-0.0015%, Ca: 0.0002-0.0050%, Mo: 0.10-0.50%, Ti: 0.001-0.05%, Cu: 0-2.0%, Nb: 0-0.05%, V: 0-0.10%, the balance: Fe and impurities, and satisfying the conditions of 2Nb+4V+Mo≦0.50, wherein a metal micro-structure of the steel pipe contains 50% or more of bainite, in an area fraction, a wall thickness of the steel pipe is 25 mm or larger, and in a scale formed on the surface of the steel pipe, metal particles consisting mainly of Ni or Cu having an average circle-equivalent diameter of 0.1-5 mm exist. A distance from a boundary between the base metal of the steel pipe and the scale to a region in which the metal particles do not exist is 20 mm or longer. 1. A seamless steel pipe for line pipe having a chemical composition consisting , by mass percent , ofC: 0.03 to 0.15%,Si: 0.50% or less,Mn: 1.0 to 2.0%,P: 0.050% or less,S: 0.005% or less,Cr: 0.1 to 1.0%,Al: 0.001 to 0.10%,N: 0.01% or less,Ni: 0.05 to 2.0%,B: 0.0003 to 0.0015%,Ca: 0.0002 to 0.0050%,Mo: 0.10 to 0.50%,Ti: 0.001 to 0.05%,Cu: 0 to 2.0%,Nb: 0 to 0.05%,V: 0 to 0.10%,the balance: Fe and impurities, andsatisfying the following formula (i),wherein a metal micro-structure of the steel pipe contains 50% or more of bainite, in an area fraction;a wall thickness of the steel pipe is 25 mm or larger; and {'br': None, '2Nb+4V+Mo≦0.50\u2003\u2003(i)'}, 'in a scale formed on the surface of the steel pipe, metal particles consisting mainly of Ni or Cu having an average circle-equivalent diameter of 0.1 to 5 μm exist, and a distance from a boundary between the base metal of the steel pipe and the scale to a region in which the metal particles do not exist is 20 μm or longerwhere each symbol of element in formula (i) represents the content (mass %) of each element.2. The seamless steel pipe for ...

Low-alloy high-strength seamless steel pipe for oil country tubular goods

Provided herein is a low-alloy high-strength seamless steel pipe. The steel pipe of the present invention has a composition that contains, in mass %, C: 0.25 to 0.50%, Si: 0.01 to 0.40%, Mn: 0.3 to 1.5%, P: 0.010% or less, S: 0.001% or less, O: 0.0015% or less, Al: 0.015 to 0.080%, Cu: 0.02 to 0.09%, Cr: 0.5 to 0.8%, Mo: 0.5 to 1.3%, Nb: 0.005 to 0.05%, B: 0.0005 to 0.0040%, Ca: 0.0010 to 0.0020%, Mg: 0.001% or less, and N: 0.005% or less, and in which the balance is Fe and incidental impurities. The steel pipe has a microstructure in which the number of oxide-base nonmetallic inclusions satisfying the composition ratios represented by predefined formulae is 10 or less per 100 mm 2 , and in which the number of oxide-base nonmetallic inclusions satisfying the composition ratios represented by other predefined formulae is 30 or less per 100 mm 2 .

A tube and a method of manufacturing a tube

A high temperature iron-chromium-aluminium (FeCrAl) alloy tube extending along a longitudinal axis, wherein the tube is formed from a continuous strip of a high temperature FeCrAl alloy and comprises a helical welded seam. The high temperature FeCrAl alloy tube is manufactured by feeding a continuous strip of the high temperature FeCrAl alloy toward a tube shaping station, helically winding the strip such that long edges of the strip abut each other and a rotating tube moving forward in a direction parallel to its longitudinal axis is formed, and continuously joining said abutting long edges together in a welding process directly when the tube is formed, whereby a welded tube comprising a helical welded seam is obtained.

X80 PIPELINE STEEL WITH GOOD STRAIN-AGING PERFORMANCE, PIPELINE TUBE AND METHOD FOR PRODUCING SAME

A X80 pipeline steel with good strain-aging performance comprises (wt. %): C: 0.02-0.05%; Mn: 1.30-1.70%; Ni: 0.35-0.60%: Ti: 0.005-0.020%; Nb: 0.06-0.09%; Si: 0.10-0.30%; Al: 0.01-0.04%; N≦0.008%; P≦0.012%; S≦0.006%; Ca: 0.001-0.003%, and balance iron and unavoidable impurities. 1. An X80 pipeline steel with good strain-aging resistance , characterized in that the contents in percentage by mass chemical elements of the steel are:02-0.05% of C, 1.30-1.70% of Mn, 0.35-0.60% of Ni, 0.005-0.020% of Ti, 0.06-0.09% of Nb, 0.10-0.30% of Si, 0.01-0.04% of Al, N≦0.008%, P≦0.012%, S≦0.006%, 0.001-0.003% of Ca, and the balance being Fe and other inevitable impurities.2. The X80 pipeline steel with good strain-aging resistance of claim 1 , characterized by further comprising 0 Подробнее

HIGH-STRENGTH STEEL, METHOD FOR MANUFACTURING HIGH-STRENGTH STEEL, STEEL PIPE AND METHOD FOR MANUFACTURING STEEL PIPE (AS AMENDED)

High-strength steel having a specified chemical composition wherein the ratio of Ti to N, Ti/N, is 2.0 to 4.0, and X (%), as calculated by equation (1): 2. The high-strength steel according to claim 1 , wherein the chemical composition of the high-strength steel further contains one claim 1 , two claim 1 , or more of:Cu: 0.50% or less, Ni: 0.50% or less, Cr: 0.50% or less, V: 0.08% or less, and Ca: 0.0005% to 0.0040%.3. A steel pipe composed of the high-strength steel according to .4. A method for manufacturing the high-strength steel according to claim 1 , the method comprisinga heating process wherein steel raw material is heated to a temperature of 1050° C. to 1200° C.,a hot rolling process wherein the steel raw material, which has been heated in the heating process, is hot-rolled under the conditions of an accumulated rolling reduction ratio of 50% or more in a temperature range of 900° C. or lower and a rolling finish temperature of 850° C. or lower, andan accelerated cooling process wherein the hot-rolled steel plate, which has been obtained in the hot rolling process, is subjected to accelerated cooling under the conditions of a cooling rate of 5° C./s or more and a cooling stop temperature of 300° C. to 450° C.5. A method for manufacturing a steel pipe claim 1 , the method comprising{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'a cold forming process wherein a steel plate composed of the high-strength steel according to is subjected to cold forming so as to be formed into a pipe shape and'}a welding process wherein butt portions of the steel plate, which has been formed into a pipe shape in the cold forming process, are welded.6. A steel pipe composed of the high-strength steel according to .7. A method for manufacturing the high-strength steel according to claim 2 , the method comprisinga heating process wherein steel raw material is heated to temperature of 1050° C. to 1200° C.,a hot rolling process wherein the steel raw material, which has been ...

STEEL FOR PIPES HAVING HIGH FATIGUE RESISTANCE, METHOD OF MANUFACTURING THE SAME, AND WELDED STEEL PIPE USING THE SAME

Provided is a steel for pipes for use in applications such as oil or gas extraction. Particularly, there are provided a steel for pipes having high fatigue resistance, a method of manufacturing the steel, and a welded steel pipe obtained using the steel. 1. A steel for pipes having high fatigue resistance , the steel comprising , by wt % , carbon (C): 0.10% to 0.15% , silicon (Si): 0.30% to 0.50% , manganese (Mn): 0.8% to 1.2% , phosphorus (P): 0.025% or less , sulfur (S): 0.005% or less , niobium (Nb): 0.01% to 0.03% , chromium (Cr): 0.5% to 0.7% , titanium (Ti): 0.01% to 0.03% , copper (Cu): 0.1% to 0.4% , nickel (Ni): 0.1% to 0.3% , nitrogen (N): 0.008% or less , and a balance of iron (Fe) and inevitable impurities , wherein chromium (Cr) , copper (Cu) , and nickel (Ni) satisfy the following formula , and {'br': None, '80<100(Cu+Ni+Cr)+(610−CT)<120 \u2003\u2003[Formula]'}, 'the steel has a microstructure comprising ferrite having a grain size of 10 μm or less and pearlite,'}where Cu, Ni, and Cr respectively refer to Cu, Ni, and Cr contents by weight, and CT refers to a coiling temperature (° C.).2. The steel of claim 1 , wherein the microstructure comprises ferrite in an area fraction of 50% to 80% and pearlite in an area fraction of 20% to 50%.3. The steel of claim 1 , further comprising molybdenum (Mo) in an amount of 0.2% or less.4. A method of manufacturing a steel for pipes having high fatigue resistance claim 1 , the method comprising:preparing a steel slab comprising, by wt %, carbon (C): 0.10% to 0.15%, silicon (Si): 0.30% to 0.50%, manganese (Mn): 0.8% to 1.2%, phosphorus (P): 0.025% or less, sulfur (S): 0.005% or less, niobium (Nb): 0.01% to 0.03%, chromium (Cr): 0.5% to 0.7%, titanium (Ti): 0.01% to 0.03%, copper (Cu): 0.1% to 0.4%, nickel (Ni): 0.1% to 0.3%, nitrogen (N): 0.008% or less, a balance of iron (Fe) and inevitable impurities;reheating the steel slab to a temperature within a range of 1100° C. to 1300° C.;rough rolling the reheated steel ...

High-strength thick-walled electric resistance welded steel pipe having excellent low-temperature toughness and method of manufacturing the same

A high-strength thick-walled electric resistance welded steel pipe has excellent low-temperature toughness and excellent HIC resistance and a yield strength of 400 MPa or more. The steel has a chemical composition consisting of C: 0.025% to 0.084%, Si: 0.10% to 0.30%, Mn: 0.70% to 1.80%, controlled amounts of P, S, Al, N, and O, Nb: 0.001% to 0.065%, V: 0.001% to 0.065%, Ti: 0.001% to 0.033%, and Ca: 0.0001% to 0.0035% on a mass percent basis and the remainder being Fe and incidental impurities, and satisfies Pcm of 0.20 or less.

SEAMLESS STEEL PIPE AND METHOD FOR PRODUCING THE SAME

There is provided a seamless steel pipe having high strength and high toughness even if having a thick wall. A seamless steel pipe according to the present embodiment consists of: in mass %, C: 0.03 to 0.08%, Si: not more than 0.25%, Mn: 0.3 to 2.0%, P: not more than 0.05%, S: not more than 0.005%, Al: 0.001 to 0.10%, Cr: 0.02 to 1.0%, Ni: 0.02 to 1.0%, Mo: 0.02 to 0.8%, N: 0.002 to 0.008%, Ca: 0.0005 to 0.005%, and Nb: 0.01 to 0.1%, the balance being Fe and impurities, and has a wall thickness of not less than 50 mm. In a cross section perpendicular to an axial direction of the seamless steel pipe, an average crystal grain size of prior austenite grains in a near surface portion is less than 80 μm, the near surface portion being a 500 μm×500 μm area centered at a position of a depth of 2 mm from a surface, and a difference between the average crystal grain size of the prior austenite grains in the near surface portion and an average crystal grain size of prior austenite grains in a central portion of a wall thickness of the cross section is less than 50 μm, the central portion being a 500 μm×500 μm area centered at a center position of the wall thickness. 1. A seamless steel pipe consisting of: in mass % ,C: 0.03 to 0.08%,Si: not more than 0.25%,Mn: 0.3 to 2.0%,P: not more than 0.05%,S: not more than 0.005%,Al: 0.001 to 0.10%,Cr: 0.02 to 1.0%,Ni: 0.02 to 1.0%,Mo: 0.02 to 0.8%,N: 0.002 to 0.008%,Ca: 0.0005 to 0.005%, andNb: 0.01 to 0.1%,the balance being Fe and impurities, andhaving a wall thickness not less than 50 mm,wherein in a cross section perpendicular to an axial direction of the seamless steel pipe, an average crystal grain size of prior austenite grains in a near surface portion is less than 80 μm, the near surface portion being a 500 μm×500 μm area centered at a position of a depth of 2 mm from a surface, andwherein a difference between the average crystal grain size of the prior austenite grains in the near surface portion and an average crystal grain ...

LOW-ALLOY STEEL PIPE FOR AN OIL WELL

A low-alloy steel pipe includes C: 0.15% to less than 0.30%, Si: 0.05 to 1.00%, Mn: 0.05 to 1.00%, P: at most 0.030%, S: at most 0.0050%, Al: 0.005 to 0.100%, 0: at most 0.005%, N: at most 0.007%, Cr: 0.10% to less than 1.00%, Mo: 1.0% to not more than 2.5%, V: 0.01 to 0.30%, Ti: 0.002 to 0.009%. Nb: 0 to 0.050%, B: 0 to 0.0050%, Ca: 0 to 0.0050%, Mo/Cr≧2.0, and the balance being Fe and impurities. The pipe has a crystal grain size number of 7.0 or more, 50 or more particles of cementite based on equivalent circle diameter and area of the matrix, MC-based alloy carbide in a number density of not less than 25/μm, and a yield strength of 758 MPa or more. 1. A low-alloy steel pipe for an oil well , comprising a chemical composition consisting of , in mass % ,C: not less than 0.15% and less than 0.30%,Si: 0.05 to 1.00%,Mn: 0.05 to 1.00%,P: not more than 0.030%,S: not more than 0.0050%,Al: 0.005 to 0.100%,O: not more than 0.005%,N: not more than 0.007%,Cr not less than 0.10% and less than 1.00%,Mo: more than 1.0% and not more than 2.5%,V: 0.01 to 0.30%,Ti: 0.002 to 0.009%,Nb: 0 to 0.050%,B: 0 to 0.0050%,Ca: 0 to 0.0050%, andthe balance being Fe and impurities,wherein the chemical composition satisfies the equation (1),the steel pipe has a crystal grain size number of prior austenite grains in accordance with ASTM E112 of not lower than 7.0,{'sup': '2', 'the steel pipe includes 50 or more particles of cementite with an equivalent circle diameter of not less than 200 nm being present in an area of 100 μmof matrix,'}{'sub': '2', 'sup': '2', 'the steel pipe includes MC-based alloy carbide in a number density of not less than 25/μm, and'} {'br': None, 'Mo/Cr≧2.0\u2003\u2003(1),'}, 'the steel pipe has a yield strength of not less than 758 MPa,'}wherein each of the chemical symbols in equation (1) is substituted for by the content of the corresponding element in mass %.2. The low-alloy steel pipe for the oil well according to claim 1 , wherein the chemical composition contains ...

HIGH STRENGTH STEEL PLATE HAVING LOW YIELD RATIO EXCELLENT IN TERMS OF STRAIN AGEING RESISTANCE, METHOD OF MANUFACTURING THE SAME AND HIGH STRENGTH WELDED STEEL PIPE MADE OF THE SAME

A steel plate has a chemical composition containing, by mass %, C: 0.03% or more and 0.08% or less, Si: 0.01% or more and 1.0% or less, Mn: 1.2% or more and 3.0% or less, P: 0.015% or less, S: 0.005% or less, Al: 0.08% or less, Nb: 0.005% or more and 0.07% or less, Ti: 0.005% or more and 0.025% or less, N: 0.010% or less, O: 0.005% or less and the balance being Fe and inevitable impurities, a structure being a dual-phase structure consisting of a bainite phase and island martensite, wherein the area fraction of the island martensite is 3% to 15%, the equivalent circle diameter of the island martensite is 3.0 μm or less, and the remainder of the structure is a bainite phase. 1. A high strength steel plate having a low yield ratio , the steel plate having a chemical composition containing , by mass % , C: 0.03% or more and 0.08% or less , Si: 0.01% or more and 1.0% or less , Mn: 1.2% or more and 3.0% or less , P: 0.015% or less , S: 0.005% or less , Al: 0.08% or less , Nb: 0.005% or more and 0.07% or less , Ti: 0.005% or more and 0.025% or less , N: 0.010% or less , O: 0.005% or less and the balance being Fe and inevitable impurities , a metallographic structure being a dual-phase structure consisting of a bainite phase and island martensite , wherein an area fraction of island martensite is 3% or more and 15% or less , wherein an equivalent circle diameter of the island martensite is 3.0 μm or less , and wherein the remainder of the metallographic structure is a bainite phase , a hardness variation in a thickness direction of ΔHV30 or less in terms of Vickers hardness , a hardness variation in a width direction of ΔHV30 or less in terms of Vickers hardness , a maximum hardness in surface portions of the steel plate of HV230 or less in terms of Vickers hardness and a yield ratio of 85% or less and an elongation of 22% or more in a full-thickness tensile test using a test piece having a shape in accordance with GOST standards.2. The steel plate according to claim 1 , ...

STEEL PIPE FOR FUEL INJECTION PIPE, AND FUEL INJECTION PIPE USING SAME

A steel pipe for a fuel injection pipe has a chemical composition consisting of, by mass %: C: 0.17 to 0.27%, Si: 0.05 to 0.40%, Mn: 0.30 to 2.00%, P: 0.020% or less, S: 0.0100% or less, O: 0.0040% or less, Ca: 0.0010% or less, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, Ti: 0.005 to 0.015%, Nb: 0.015 to 0.045%, Cr: 0 to 1.00%, Mo: 0 to 1.00%, Cu: 0 to 0.50%, Ni: 0 to 0.50%, V: 0 to 0.15%, and the balance: Fe and impurities. The metal micro-structure consists substantially of tempered martensite, or tempered martensite and tempered bainite. The hardness is within the range of 350 to 460 HV1. A lattice spacing of a (211) diffraction plane measured by CoKα characteristic X-ray diffraction is 1.1716 Å or less, and a half-value width of the (211) diffraction plane is 1.200° or less. The number density of cementite having a diameter of 50 nm or more is 20/μmor less.

HIGH-STRENGTH SEAMLESS STAINLESS STEEL TUBE FOR OIL COUNTRY TUBULAR GOODS AND METHOD OF MANUFACTURING THE SAME

A steel material has a chemical composition containing, by mass %, C: 0.005% or more and 0.06% or less, Si: 0.05% or more and 0.5% or less, Mn: 0.2% or more and 1.8% or less, Cr: 15.5% or more and 18.0% or less, Ni: 1.5% or more and 5.0% or less, V: 0.02% or more and 0.2% or less, Al: 0.002% or more and 0.05% or less, N: 0.01% or more and 0.15% or less, O: 0.006% or less, and further contains one or more of Mo: 1.0% or more and 3.5% or less, W: 3.0% or less and Cu: 3.5% or less, in which Cr+0.65Ni+0.60Mo+0.30W+0.55Cu-20C≧19.5 and Cr+Mo+0.50W+0.30Si-43.5C-0.4Mn—Ni-0.3Cu-9N≧11.5 are satisfied, is made into a seamless steel tube by performing heating and hot rolling. 16.-. (canceled)7. A method of manufacturing a high-strength seamless stainless steel tube for oil country tubular goods having a wall thickness of more than 25.4 mm , comprising:heating a steel material;hot rolling including piercing rolling the steel material into a seamless steel tube; andcooling the seamless steel tube to room temperature at a cooling rate equal to or more than an air-cooling rate, the steel material having a chemical composition containing, by mass %,C: 0.005% or more and 0.06% or less, Si: 0.05% or more and 0.5% or less,Mn: 0.2% or more and 1.8% or less, P: 0.03% or less,S: 0.005% or less, Cr: 15.5% or more and 18.0% or less,Ni: 1.5% or more and 5.0% or less, V: 0.02% or more and 0.2% or less,Al: 0.002% or more and 0.05% or less, N: 0.01% or more and 0.15% or less, O: 0.006% or less, and [{'br': None, 'Cr+0.65Ni+0.60Mo+0.30W+0.55Cu-20C≧19.5\u2003\u2003(1),'}, {'br': None, 'Cr+Mo+0.50W+0.30Si-43.5C-0.4Mn—Ni-0.3Cu-9N≧11.5\u2003\u2003(2),'}], 'further containing one, two or more selected from among Mo: 1.0% or more and 3.5% or less, W: 3.0% or less and Cu: 3.5% or less and the balance being Fe and inevitable impurities, wherein expressions (1) and (2) are satisfied, the hot rolling including piercing rolling is performed under conditions such that the total rolling reduction in a ...

HIGH-STRENGTH SEAMLESS STAINLESS STEEL PIPE FOR OIL COUNTRY TUBULAR GOODS AND METHOD FOR MANUFACTURING THE SAME

A high-strength seamless stainless steel pipe for oil country tubular goods that is excellent in terms of hot workability, sulfide stress cracking resistance, and corrosion resistance, and a method for manufacturing the steel pipe. The steel pipe has a chemical composition containing Cr and Ni so that the relationship Cr/Ni≦5.3 is satisfied. A microstructure of the steel pipe includes mainly a tempered martensite phase. Additionally, a surface layer microstructure of the steel pipe includes a phase which looks white when subjected to etching with a Vilella etching solution, the phase having a thickness in the wall thickness direction from the outer surface of the pipe of 10 μm or more and 100 μm or less and dispersing in the outer surface of the pipe in an amount of 50% or more in terms of area fraction. 1. A high-strength seamless stainless steel pipe for oil country tubular goods , the steel pipe comprising: {'br': None, 'Cr/Ni≦5.3\u2003\u2003(1),'}, 'a chemical composition containing Cr and Ni and that satisfies expression (1)'}where Cr and Ni respectively denote the contents (mass %) of the corresponding chemical elements; anda microstructure including mainly a tempered martensite phase,wherein a surface layer microstructure of the steel pipe includes a phase which looks white when subjected to etching with a Vilella etching solution, the phase having a thickness in a wall thickness direction from an outer surface of the pipe of 10 μm or more and 100 μm or less, and dispersing in the outer surface of the pipe in an amount of 50% or more in terms of area fraction.2. The high-strength seamless stainless steel pipe for oil country tubular goods according to claim 1 , wherein the chemical composition of the steel pipe comprises:C: 0.005% or more and 0.05% or less, by mass %,Si: 0.05% or more and 1.50% or less, by mass %,Mn: 0.2% or more and 1.8% or less, by mass %,P: 0.02% or less, by mass %,S: 0.005% or less, by mass %,Cr: 11% or more and 18% or less, by mass %,Ni: ...

STEEL FOR HOT FORMING

A steel for hot forming having the following composition in weight %: 5. The strip claim 1 , sheet claim 1 , blank claim 1 , or tube produced with the steel according to .6. The strip claim 5 , sheet claim 5 , blank or tube according to claim 5 , pre-coated with a layer of aluminium or an aluminium based alloy claim 5 , or pre-coated with a layer of zinc or a zinc based alloy.7. The strip claim 6 , sheet claim 6 , blank or tube according to claim 6 , wherein the pre-coating comprised 5 to 13 wt % silicon and/or less than 5 wt % iron claim 6 , the remainder being aluminium claim 6 , the pre-coating having a thickness between 10 and 40 μm per side.8. The strip claim 7 , sheet claim 7 , blank or tube according to claim 7 , wherein the pre-coating comprised 8 to 12 wt % silicon and/or 2 to 5 wt % iron claim 7 , the remainder being aluminium.9. The strip claim 6 , sheet claim 6 , blank or tube according to claim 6 , wherein the pre-coating is an iron-zinc diffusion coating obtained by heat treating a zinc layer claim 6 , the zinc layer comprising Al<0.18 wt % and Fe<15 wt % claim 6 , the remainder being zinc and traces of other elements claim 6 , the pre-coating preferably having a thickness between 5 and 15 μm per side.10. The strip claim 6 , sheet claim 6 , blank or tube according to claim 6 , wherein the pre-coating comprises 0.5 to 4 wt % Al and 0.5 to 3.2 wt % Mg claim 6 , the remainder being zinc and traces of other elements claim 6 , the pre-coating having a thickness between 5 and 15 μm per side.11. The method for producing a hot formed product using the strip claim 6 , sheet claim 6 , blank or tube according to claim 6 , using the following steps:providing a blank, for instance by cutting the strip or sheet, or tubeheating the blank or tube to a temperature above the Ac1 temperature of the steel, to a temperature of at most 1000° C.transporting the heated blank or tube into a hot forming pressforming the blank or tube into a product in the press{'sub': 'S', ' ...

HIGH STRENGTH MICRO ALLOYED STEEL SEAMLESS PIPE FOR SOUR SERVICE AND HIGH TOUGHNESS APPLICATIONS

Micro alloyed steels with a yield strength of at least 485 MPa (70 ksi) with outstanding toughness behavior, good weldability and improved sulphide stress cracking resistance for line pipes, for applications as process pipes, flowlines or risers in the oil and gas industry. Tubular products, such as seamless pipes, can be made from this steel. A process for manufacturing tubular products can be performed with this steel. The seamless pipes can be used for line pipes, flowlines and risers in the oil and gas industry. 1. A steel presenting a yield strength greater than or equal to 485 MPa and having a chemical composition consisting of , in weight % , relative to the total weight of said chemical composition ,0.05≤C≤0.100.15≤Si≤0.351.20≤Mn≤1.500.02≤Cr≤0.100.10 Подробнее

DUAL PHASE STAINLESS STEEL PIPE AND MANUFACTURING METHOD THEREOF

A dual phase stainless steel pipe includes tensile yield strength YSof 689.1 MPa to 1000.5 MPa in a pipe axis direction of the dual phase stainless steel pipe, in which the tensile yield strength YS, a compressive yield strength YSin the pipe axis direction, a tensile yield strength YSin a pipe circumferential direction of the dual phase stainless steel pipe, and a compressive yield strength YSin the pipe circumferential direction satisfy all Expressions (1) to (4), 1. A dual phase stainless steel pipe , comprising:{'sub': 'LT', 'a tensile yield strength YSof 689.1 MPa to 1000.5 MPa in a pipe axis direction of the dual phase stainless steel pipe,'}{'sub': LT', 'LC', 'CT', 'CC, 'claim-text': [{'br': None, 'i': YS', '/YS, 'sub': LC', 'LT, '0.90≦≦1.11\u2003\u2003(1)'}, {'br': None, 'i': YS', '/YS, 'sub': CC', 'CT, '0.90≦≦1.11\u2003\u2003(2)'}, {'br': None, 'i': YS', '/YS, 'sub': CC', 'LT, '0.90≦≦1.11\u2003\u2003(3)'}, {'br': None, 'i': YS', '/YS, 'sub': CT', 'LT, '0.90≦≦1.11\u2003\u2003(4).'}], 'wherein the tensile yield strength YS, a compressive yield strength YSin the pipe axis direction, a tensile yield strength YSin a pipe circumferential direction of the dual phase stainless steel pipe, and a compressive yield strength YSin the pipe circumferential direction satisfy all Expressions (1) to (4),'}2. The dual phase stainless steel pipe according to claim 1 ,wherein the dual phase stainless steel pipe contains, in mass %,C: 0.008% to 0.03%;Si: 0% to 1%;Mn: 0.1% to 2%;Cr: 20% to 35%;Ni: 3% to 10%;Mo: 0% to 4%;W: 0% to 6%;Cu: 0% to 3%; andN: 0.15% to 0.35%, anda remainder composed of Fe and impurities.3. The dual phase stainless steel pipe according to claim 1 ,wherein the dual phase stainless steel pipe is manufactured by performing a straightening and a low temperature heat treatment at a heat treatment temperature of 350° C. to 450° C. after being subjected to cold working.4. The dual phase stainless steel pipe according to claim 3 ,wherein the dual phase stainless ...

METHOD OF PRODUCING COPPER ALLOY MATERIAL HAVING HIGH STRENGTH AND EXCELLENT BENDABILITY FOR AUTOMOBILE AND ELECTRICAL/ELECTRONIC COMPONENTS

The present invention relates a method of producing a copper-titanium (Cu—Ti)-based copper alloy, and provides a method of producing a copper alloy material for automobile and electrical/electronic components requiring high performance by satisfying high strength and bendability together. 1. A method of producing a copper alloy material for automobile and electrical and electronic components , comprising:(a) melting and casting 1.5 to 4.3 wt % titanium (Ti), 0.05 to 1.0 wt % nickel (Ni), a remainder of copper (Cu), and inevitable impurities of 0.8 wt % or less to obtain a slab, wherein the inevitable impurities include one or more elements selected from the group consisting of Sn, Co, Fe, Mn, Cr, Zn, Si, Zr, V and P, and a weight ratio of Ti to Ni (Ti/Ni) is 10 Подробнее

HIGH-STRENGTH SEAMLESS STAINLESS STEEL PIPE AND METHOD OF MANUFACTURING HIGH-STRENGTH SEAMLESS STAINLESS STEEL PIPE

A high-strength seamless stainless steel pipe has a composition including, by mass %, 0.05% or less C, 1.0% or less Si, 0.1 to 0.5% Mn, 0.05% or less P, 0.005% or less S, more than 16.0% to 18.0% or less Cr, more than 2.0% to 3.0% or less Mo, 0.5 to 3.5% Cu, 3.0% or more and less than 5.0% Ni, 0.01 to 3.0% W, 0.01 to 0.5% Nb, 0.001 to 0.3% Ti, 0.001 to 0.1% Al, less than 0.07% N, 0.01% or less O, and Fe and unavoidable impurities as a balance, wherein the steel pipe has a microstructure including a tempered martensite phase forming a main phase, 20 to 40% of a ferrite phase in terms of volume ratio, and 25% or less of a residual austenite phase in terms of volume ratio, an average grain size of the ferrite phase is 40 μm or less, and a sum of amounts of Ti and Nb precipitated as precipitates having a grain size of 2 μm or less is 0.06 mass % or more, whereby the steel pipe has high strength where yield strength YS is 758 MPa or more and high toughness where an absorbing energy value vEin a Charpy impact test at a test temperature of −10° C. is 40 J or more. 14.-. (canceled)5. A high-strength seamless stainless steel pipe having a composition comprising , by mass % , 0.05% or less C , 1.0% or less Si , 0.1 to 0.5% Mn , 0.05% or less P , 0.005% or less S , more than 16.0% to 18.0% or less Cr , more than 2.0% to 3.0% or less Mo , 0.5 to 3.5% Cu , 3.0% or more and less than 5.0% Ni , 0.01 to 3.0% W , 0.01 to 0.5% Nb , 0.001 to 0.3% Ti , 0.001 to 0.1% Al , less than 0.07% N , 0.01% or less 0 , and Fe and unavoidable impurities as a balance , wherein the steel pipe has a microstructure comprising a tempered martensite phase forming a main phase , 20 to 40% of a ferrite phase in terms of volume ratio , and 25% or less of a residual austenite phase in terms of volume ratio , an average grain size of the ferrite phase is 40 μm or less , and a sum of amounts of Ti and Nb precipitated as precipitates having a grain size of 2 μm or less is 0.06 mass % or more , whereby the ...

HIGH STRENGTH ELECTRIC RESISTANCE WELDED STEEL PIPE, METHOD FOR PRODUCING STEEL PLATE FOR HIGH STRENGTH ELECTRIC RESISTANCE WELDED STEEL PIPE USE, AND METHOD FOR PRODUCING HIGH STRENGTH ELECTRIC RESISTANCE WELDED STEEL PIPE

Electric resistance welded steel pipe securing the high strength and high toughness demanded from oil well pipe in recent years. The metal structure in a region having a width of 0.5 mm in both the thickness directions from a reference point, when using a point defined as a point ¼ of the thickness in the thickness direction from the surface in the base material part of the steel pipe as the reference point, consists of polygonal ferrite: 10 area % or less and a balance: bainitic ferrite. The thickness is 15 mm or more. 1. High strength electric resistance welded steel pipe characterized by having a chemical composition consisting of , by mass % ,C: 0.040 to 0.070%,Si: 0.10 to 0.50%,Mn: 1.60 to 2.00%,Nb: 0.020 to 0.080%,V: 0.060% or less,Ti: 0.010 to 0.025%,Mo: 0.20 to 0.40%,Ni: 0.10 to 0.50%,Al: 0.050% or less, a balance of Fe and unavoidable impurities, wherein', 'when using a point defined as a point ¼ of the thickness in the thickness direction from the surface in the base material part of the steel pipe as a reference point, the metal structure in a region having a width of 0.5 mm in both the thickness directions from the reference point as a center consists of polygonal ferrite: 10 area % or less and a balance of bainitic ferrite, and', 'a thickness is 15.0 to 19.8 mm., '3 Mo %+Ni %: more than 1.00%, and'}2. The high strength electric resistance welded steel pipe according to claim 1 , wherein the chemical composition further comprises claim 1 , by mass %P: 0.030% or less,S: 0.004% or less,N: 0.006% or less, andO: 0.004% or less.3. The high strength electric resistance welded steel pipe according to claim 1 , wherein the chemical composition further comprises claim 1 , by mass % claim 1 , one or two or more ofCu: 0.10 to 0.50%,Cr: 0.05 to 0.50%Ca: 0.0005 to 0.0040% andREM: 0.0005 to 0.0050%.4. The high strength electric resistance welded steel pipe according to claim 3 , wherein (3Mo %+Ni %+Cu %) is more than 1.20%.5. The high strength electric resistance ...

Steel for oil country tubular goods and method of producing the same

A steel for oil country tubular goods includes, as a chemical composition, by mass %, C, Si, Mn, Al, Mo, P, S, O, N, and a balance containing Fe and impurities, wherein a full width at half maximum HW of a crystal plane corresponding to a (211) crystal plane of an α phase and a carbon content expressed in mass % in the chemical composition satisfy HW×C 1/2 ≦0.38, the carbon content and a molybdenum content expressed in mass % in the chemical composition satisfy C×Mo≧0.6, a number of M 2 C carbides having a hexagonal crystal structure and having an equivalent circle diameter of 1 nm or more is 5 pieces or more per one square micron, and an yield strength is 758 MPa or more.

Classes of Steels for Tubular Products

The present disclosure is directed and formulations and methods to provide alloys having relative high strength and ductility. The alloys may be provided in seamless tubular form and characterized by their particular alloy chemistries and identifiable crystalline grain size morphology. The alloys are such that they include boride pinning phases. In what is termed a Class 1 Steel the alloys indicate tensile strengths of 700 MPa to 1400 MPa and elongations of 10-70%. Class 2 Steel indicates tensile strengths of 800 MPa to 1800 MPa and elongations of 5-65%. Class 3 Steel indicates tensile strengths of 1000 MPa to 2000 MPa and elongations of 0.5-15%. 1. A method for forming a seamless tubular component comprising:supplying a metal alloy comprising Fe at a level of 48.00 to 88.00 atomic percent, Ni at 0 to 16.00 atomic percent, Cr at 0 to 32.00 atomic percent, Mn at 0 to 21.00 atomic percent, B at 1.0 to 8.00 atomic percent, Si at 1.00 to 14.00 atomic percent;melting said alloy and solidifying to provide an alloy including a matrix grain size of 500 nm to 20,000 nm and a boride grain size of 25 nm to 500 nm;mechanical stressing said alloy and/or heating and forming a seamless tubular component having at least one of the following grain size distributions and mechanical property profiles, wherein said boride grains provide pinning phases that resist coarsening of said matrix grains:(a) matrix grain size of 500 nm to 20,000 nm, boride grain size of 25 nm to 500 nm, precipitation grain size of 1 nm to 200 nm wherein said alloy indicates a yield strength of 400 MPa to 1300 MPa, tensile strength of 700 MPa to 1400 MPa and tensile elongation of 10 to 70%; or(b) refined matrix grain size of 100 nm to 2000 nm, precipitation grain size of 1 nm to 200 nm, boride grain size of 200 nm to 2,500 nm where the alloy has a yield strength of 300 MPa to 800 MPa.2. The method of wherein said melting is achieved at temperatures in the range of 1100° C. to 2000° C. and solidification is ...

Hot coil for line pipe use and method of production of same

The present invention provides a hot coil for line pipe use which can reduce deviation in ordinary temperature strength and improve low temperature toughness despite the numerous restrictions in production conditions due to the coiling step and provides a method of production of the same, specifically makes the steel plate stop for a predetermined time between rolling passes in the recrystallization temperature range and performs cooling by two stages after hot rolling so as to thereby make the steel structure at the center part of plate thickness and effective crystal grain size of 3 to 10 μm, make the total of the area ratios of bainite and acicular ferrite 60 to 99%, and make the absolute value of A-B 0 to 30% when the totals of the area ratios of bainite and acicular ferrite at any two portions are designated as respectively A and B.

METHOD OF FORMING AND HEAT TREAATING COILED TUBING

Described herein are coiled tubes with improved and varying properties along the length that are produced by using a continuous and dynamic heat treatment process (CDHT). Coiled tubes can be uncoiled from a spool, subjected to a CDHT process, and coiled onto a spool. A CDHT process can produce a “composite” tube such that properties of the tube along the length of the tube are selectively varied. For example, the properties of the tube can be selectively tailored along the length of the tube for particular application for which the tube will be used. 123-. (canceled)24. A method of forming and heat treating a coiled tube , the method comprising:welding a plurality of steel strips together end-to-end to form a plurality of end-to-end welded strips and longitudinally welding the plurality of end-to-end welded strips to form a tube with a substantially constant inner diameter, outer diameter, and wall thickness along at least a first portion, a second portion, and a third portion, the third portion being disposed between the first portion and the second portion, said tube having one or more microstructures; andafter forming the tube, performing a continuous and dynamic heat treatment (CDHT) process comprising a continuous quench and temper heat treatment along the first portion, the second portion, and the third portion, thereby modifying the one or more microstructures of the tube and thereby resulting in a post heat treatment (PHT) tube with a second microstructure comprising a uniformity of microstructure across (a) the plurality of steel strips, (b) a plurality of end-to-end welds joining the steel strips, and (c) a plurality of longitudinal welds joining the plurality of steel strips, and wherein the PHT tube after the continuous quench and temper process has at least 80% tempered martensite in the first, second, and third portions of the PHT tube; andcoiling the PHT tube to form a coiled tube.25. The method of claim 24 , wherein the step of coiling the PHT tube ...

STAINLESS STEEL SEAMLESS PIPE

A stainless steel seamless pipe having high strength, excellent low-temperature toughness and corrosion resistance, and a composition including, in mass %, C: 0.06% or less, Si: 1.0% or less, Mn: 0.01% or more and 1.0% or less, P: 0.05% or less, S: 0.005% or less, Cr: 14.0% or more and 17.0% or less, Mo: more than 3.80% and 6.0% or less, Cu: more than 1.03% and 3.5% or less, Ni: 3.5% or more and 6.0% or less, Al: 0.10% or less, N: 0.10% or less, O: 0.010% or less, and the balance is Fe and incidental impurities. Elements C, Si, Mn, Cr, Ni, Mo, Cu, and N satisfy a predetermined relationship. The stainless steel seamless pipe has a yield strength of 862 MPa or more and has a microstructure that contains at least 40% martensitic phase, at most 60% ferrite phase, and at most 30% retained austenite phase by volume. 1. A stainless steel seamless pipe having a composition comprising , in mass % ,C: 0.06% or less,Si: 1.0% or less,Mn: 0.01% or more and 1.0% or less,P: 0.05% or less,S: 0.005% or less,Cr: 14.0% or more and 17.0% or less,Mo: more than 3.80% and 6.0% or less,Cu: more than 1.03% and 3.5% or less,Ni: 3.5% or more and 6.0% or less,Al: 0.10% or less,N: 0.10% or less, andO: 0.010% or less, anda balance being Fe and incidental impurities,wherein {'br': None, '13.0≤−5.9×(7.82+27C−0.91Si+0.21Mn−0.9Cr+Ni−1.1Mo+0.2Cu+11N)≤50.0\u2003\u2003(1)'}, 'C, Si, Mn, Cr, Ni, Mo, Cu, and N satisfy the following Formula (1)where C, Si, Mn, Cr, Ni, Mo, Cu, and N represent the content of each element in mass %,the stainless steel seamless pipe has a microstructure that contains at least 40% martensitic phase, at most 60% ferrite phase, and at most 30% retained austenite phase by volume, andthe stainless steel seamless pipe has a yield strength of 862 MPa or more.2. The stainless steel seamless pipe according to claim 1 , wherein the composition further comprises claim 1 , in mass % claim 1 , at least one selected from the group consisting of group A claim 1 , group B claim 1 , group C ...

Components made of a steel alloy and method for producing high-strength components

The invention concerns a component made of a steel alloy comprising iron and as alloying element copper, in particular consisting of (in wt % in relation to the total alloy, wherein the sum of all constituents equals 100 wt %) iron≧96, carbon 0.04 to 0.12, copper 0.5 to 2.0, manganese+silicon+chromium+nickel 0.5 to 2.5, titanium 0 to 0.1, boron 0 to 0.005, and typical unavoidable impurities. In the production of semi-finished goods and of components, a combination of cold working and annealing treatment below the recrystallization temperature is used in order to thus obtain advantageous properties with regard to strength and ductility.

Austenitic Stainless Steel Material

There is provided an austenitic stainless steel material having a consistent high-strength across the overall length of the steel material, which has a chemical composition consisting of, in mass percent: C: 0.10% or less, Si: 1.0% or less, Mn: 3 to 8%, P: 0.05% or less, S: 0.03% or less, Ni: 10 to 20%, Cr: 15 to 30%, N: 0.20 to 0.70%, with the balance being Fe and impurities, the austenitic stainless steel material having a grain size number of 6.0 or greater, the grain size number conforming to ASTM E 112 tensile strength of the austenitic stainless steel material is 800 MPa or more, and the difference between the maximum value and the minimum value of the tensile strength is 50 MPa or smaller. The number of alloy carbo-nitrides having a circle equivalent diameter of larger than 1000 nm in the steel is 10/mmor more. 1. An austenitic stainless steel material comprising:a chemical composition consisting of, in mass percent:C: 0.10% or less;Si: 1.0% or less;Mn: 3 to 8%;P: 0.05% or less;S: 0.03% or less;Ni: 10 to 20%;Cr: 15 to 30%;N: 0.20 to 0.70%;Mo: 0 to 5.0%;V: 0 to 0.5%; andNb: 0 to 0.5%, with the balance being Fe and impurities,{'sup': '2', 'wherein a grain size number conforming to ASTM E 112 is 6.0 or greater, a tensile strength is 800 MPa or more, a difference between a maximum value and a minimum value of the tensile strength is 50 MPa or less, and a number of alloy carbo-nitrides with circle equivalent diameters of larger than 1000 nm in steel is 10/mmor more.'}2. The austenitic stainless steel material according to claim 1 , wherein the chemical composition contains one claim 1 , or two or more elements selected from the group consisting of:Mo: 1.5 to 5.0%;V: 0.1 to 0.5%; andNb: 0.1 to 0.5%.3. The austenitic stainless steel material according to claim 1 , wherein a difference between a maximum value and a minimum value of the grain size number is 1.5 or smaller.4. The austenitic stainless steel material according to claim 1 , wherein the austenitic ...

APPARATUS LINE FOR MANUFACTURING SEAMLESS STEEL PIPE AND TUBE AND METHOD OF MANUFACTURING DUPLEX SEAMLESS STAINLESS STEEL PIPE

An apparatus line for manufacturing seamless steel pipes and tubes includes: a heating apparatus for heating a steel raw material; a piercing apparatus for piercing the heated steel raw material thus forming a hollow material; and a rolling apparatus for applying working to the hollow material to form a seamless steel pipe having a predetermined shape. A cooling apparatus is arranged on an exit side of the rolling apparatus. A heated steel raw material is worked by the rolling apparatus after being pierced by the piercing apparatus, and thereafter, using a surface temperature of a hollow piece before being cooled by the cooling apparatus as a cooling start temperature, the hollow piece is cooled to a cooling stop temperature differing by 50° C. or more from the cooling start temperature and being equal to or above 600° C. at an average cooling speed of 1.0° C./s or more in terms of an outer surface temperature. 1. An apparatus line for manufacturing seamless steel pipes and tubes comprising:a heating apparatus for heating a steel raw material;a piercing apparatus for piercing the heated steel raw material to form a hollow material;a rolling apparatus for applying hot working to the hollow material to form a seamless steel pipe having a predetermined size; anda cooling apparatus arranged on an exit side of the rolling apparatus.2. The apparatus line for manufacturing seamless steel pipes and tubes according to claim 1 , whereina heat-retention apparatus having a heating function is arranged on an exit side of the cooling apparatus.3. The apparatus line for manufacturing seamless steel pipes and tubes according to claim 1 , whereinthe cooling apparatus has a cooling capability where an average cooling speed at a position on an outer surface of a material to be cooled is set to 1.0° C./s or more.4. The apparatus line for manufacturing seamless steel pipes and tubes according to claim 2 , whereinthe heat-retention apparatus has a heat-retention capability where an ...

AIR CONDITIONER

The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 11 kW to 16 kW, inclusive, and uses R134a as a refrigerant circulating therein, and since a refrigerant pipe therein is made of a ductile stainless steel material having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof, the refrigerant pipe can maintain strength and hardness as good as or better than those of a copper pipe, while also maintaining good processability. 1. An air conditioner comprising:an outdoor unit comprising a compressor, an outdoor heat exchanger, a main expansion device, and a refrigerant pipe configured to connect the outdoor heat exchanger to the main expansion device;an indoor unit comprising an indoor heat exchanger; anda connection pipe configured to connect the outdoor unit to the indoor unit,wherein the air conditioner has refrigeration capacity of 11 kW to 16 kW,an R134a is used as the refrigerant,the refrigerant pipe is made of a ductile stainless steel material having a delta ferrite matrix structure of 1% or less on the basis of a grain area, andthe refrigerant pipe comprises a suction pipe that guides suction of a refrigerant into the compressor and has an outer diameter of 12.70 mm.2. The air conditioner according to claim 1 , wherein the refrigerant pipe further comprises a discharge pipe that guides discharge of the refrigerant compressed in the compressor and has an outer diameter of 7.94 mm.3. The air conditioner according to claim 2 , wherein the suction pipe has an inner diameter of 12.30 mm or less claim 2 , and the discharge pipe has an inner diameter of 7.66 mm or less.4. The air conditioner according to claim 1 , wherein the refrigerant pipe further comprises a discharge pipe that guides discharge of the refrigerant compressed in the compressor and has an outer diameter of 9.52 mm.5. The air conditioner according to claim 4 , wherein the ...

METHOD AND DEVICE FOR GENERATING DEFORMATION TWINNING IN A METAL

A method of generating twin lamellas in a metal body includes the steps of introducing the metal body into a chamber, filling the chamber with a cooling medium having a temperature that will enable generation of twin lamellas in the metal body upon deformation thereof, and deforming the metal body while the latter is surrounded by the cooling medium. The cooling medium surrounds the metal body upon deformation of the latter is in a gaseous state. The present disclosure also relates to a device for generating twin lamellas in the metal body, the device including a chamber, a chamber inlet connected to a cooling medium source, and a deformation device arranged to deform the metal body. The deformation device is positioned inside the chamber so that the metal body will be surrounded by the cooling medium in a gaseous state while being deformed by the deformation device. 1. A method of generating twin lamellas in a metal body , comprising the steps of:introducing said metal body into a chamber;filling said chamber with a cooling medium having a temperature arranged to enable generation of twin lamellas in the metal body upon deformation thereof; anddeforming said metal body while the metal body is surrounded by said cooling medium, wherein the cooling medium surrounding said metal body upon deformation of the metal body is in a gaseous state.2. The method according to claim 1 , wherein the temperature inside the chamber is controlled by controlled introduction of said cooling medium into the chamber in at least two different locations within the chamber claim 1 , wherein the cooling medium in a first location is directed directly onto the metal body being deformed claim 1 , and in a second location is directed onto a deformation device used to deform said metal body.3. The method according to claim 1 , wherein the cooling medium has a temperature in the range of about −80° C. to about −195° C.4. The method according to claim 1 , wherein said cooling medium consists ...

METHOD FOR PRODUCING A COMPONENT BY HOT FORMING A PRE-PRODUCT MADE OF STEEL

A method for producing a component by hot forming a pre-product made of steel is disclosed. The pre-product is heated to a forming temperature and is then reshaped, said component having a bainitic microstructure with a minimum tensile strength of 800 MPa after the forming process. In the process, the pre-product with the specified alloy composition is heated to a temperature below the Atransformation temperature, said pre-product already consisting of a steel with a microstructure made of at least 50% bainite. 115.-. (canceled)17. The method of claim 16 , wherein the microstructure of the pr-product is composed of at least 70% bainite and a content of residual austenite+martensite is<10% and the remainder is ferrite.20. The method of claim 16 , wherein during the heating step only portions of the pre-product are heated to forming temperature claim 16 , and optionally above the Actransformation temperature.21. The method of claim 16 , wherein the pre-product is heated to a temperature below 720° C.22. The method of claim 21 , wherein the pre-product is heated to a temperature in a ranged from 400 to 720° C.23. The method of claim 22 , wherein the pre-product is heated to a temperature in a ranged from 500 to 700° C.24. The method of claim 16 , further comprising prior to the heating step claim 16 , is providing the pre-product with a metallic or lacquer-like coating.25. The method of claim 24 , wherein the metallic coating contains Zn and/or Mn and/or Al and/or Si.26. The method of claim 16 , wherein the heating to forming temperature is accomplished inductively claim 16 , conductively claim 16 , or by means of radiation.27. The method of claim 16 , wherein the pre-product is a metal plate or a tube.28. The method of claim 27 , wherein the metal plate is made of hot strip or cold strip.29. The method of claim 27 , wherein the tube is a seamlessly hot rolled tube or a welded tube made of hot strip or cold strip.30. The method of claim 29 , wherein the tube is ...

Nitrided Track Pin for Track Chain Assembly of Machine

A track pin for a track chain assembly includes a body made from a steel alloy. The steel alloy has a composition comprising iron, a nitride-forming element, and silicon. The composition of the steel alloy comprises at least 0.5 percent by weight of silicon. The body includes an external nitrided surface.

High Elastic Modulus Shafts and Method of Manufacture

High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus <111> crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded <111> single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular <111> texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels. 1. A method of producing a high elastic modulus shaft from an alloy , the method comprising:providing a single crystal cylinder of the alloy, the single crystal cylinder having a longitudinal axis, the single crystal cylinder being seeded so that a high modulus <111> direction is at least substantially parallel to the longitudinal axis;hot working the cylinder to achieve a cylindrically shaped shaft of a desired size;heat treating the shaft after the hot working step in order to subject the shaft to a limited recrystallization process at a temperature below a recrystallization temperature of the alloy in order to produce the a shaft having a desired elastic modulus.2. The method of wherein the alloy is an iron based alloy.3. The method of wherein the alloy is steel.4. The method of wherein the hot working step comprises axisymmetrically hot working the cylinder.5. A shaft formed by the method of and wherein the heat treating step is direct age heat treating.6. The method of wherein subsequent to the heat treating a Young's modulus in the <111> direction is greater than about 37 Mpsi (255 GPa).7. The method of wherein subsequent to the heat treating a Young's modulus in the ...

Alloy with High Core Hardness Suitable for Rapid Nitriding

The disclosure is directed to an alloy steel suitable for rapid nitriding, having a steel composition including by weight (%): Carbon: from 0.2 to 0.4; Manganese: from 0.50 to 1.60; Silicon: from 0.50 to 2.0; Chromium: from 0.40 to 1.5; Vanadium: from 0.03 to 0.30; Aluminum: from 0.07 to 0.30; and a balance of iron and other residual elements, where amounts of nickel and molybdenum are limited. 1. An alloy steel suitable for rapid nitriding , having a steel composition comprising by weight (%):Carbon: from 0.2 to 0.4;Manganese: from 0.50 to 1.60;Silicon: from 0.50 to 2.0;Chromium: from 0.40 to 1.5;Vanadium: from 0.03 to 0.30;Aluminum: from 0.07 to 0.30; andIron and other residual elements: balance.2. The alloy steel suitable for rapid nitriding according to claim 1 , wherein the silicon content in the steel composition is in range of from 1.0 to 2.0% by weight.3. The alloy steel suitable for rapid nitriding according to claim 1 , wherein the silicon content in the steel composition is in a range of from 1.5 to 2.0% by weight.4. The alloy steel suitable for rapid nitriding according to claim 1 , wherein the steel composition further comprises by weight:Nickel: 1.0% or less.5. The alloy steel suitable for rapid nitriding according to claim 1 , wherein the steel composition further comprises by weight:Molybdenum: 0.1% or less.6. The alloy steel suitable for rapid nitriding according to claim 1 , wherein the steel composition further comprises by weight:a total amount of nickel and molybdenum: 1.0% or less.7. The alloy steel suitable for rapid nitriding according to claim 1 , wherein the steel composition further comprises by weight:at least one of titanium and niobium: 0.1% or less.8. The alloy steel suitable for rapid nitriding according to claim 1 , wherein the steel composition consists essentially of by weight (%):Carbon: from 0.2 to 0.4;Manganese: from 0.50 to 1.60;Silicon: from 0.50 to 2.0;Chromium: from 0.40 to 1.5;Vanadium: from 0.03 to 0.30;Aluminum: from 0.07 ...

STEEL MATERIAL FOR A TORSIONALLY STRESSED COMPONENT, METHOD FOR PRODUCING A TORSIONALLY STRESSED COMPONENT FROM SAID STEEL MATERIAL, AND COMPONENT MADE THEREOF

A steel material for a torsionally stressed component, such as a driveshaft, having a minimum tensile strength of 800 MPs, and the microstructure consists of more than 50 vol. % of bainite, having an alloy with the following composition in wt. %: C: 0.02 to 0.3; Si: up to 0.7; Mn: 1.0 to 3.0; P: max. 0.02; S: max. 0.01; N: max. 0.01; Al: up to 0.1; Cu: up to 0.2; Cr: up to 3.0; Ni: up to 0.3; Mo: up to 0.5; Ti: up to 0.2; V: up to 0.2; Nb: up to 0.1; B: up to 0.01; where 0.02≤Nb+V+Ti≤0.25, residual iron, and smelting impurities. The steel material is inexpensive and has good torsional fatigue strength when used for a torsionally stressed component. The invention also relates to a method for producing a component made of the material and to such a component. 1. A steel material for a torsionally stressed component , in which the steel material has a minimum tensile strength of 800 MPa and the microstructure consists of more than 50 vol. % bainite , having an alloy with the following composition in wt. %:C: 0.02 to 0.3;Si: up to 0.7;Mn: 1.0 to 3.0;P: max. 0.02;S: max. 0.01;N: max. 0.01;Al: up to 0.1;Cu: up to 0.2;Cr: up to 1.0;Ni: up to 0.3;Mo: up to 0.5;Ti: up to 0.2;V: up to 0.2;Nb: up to 0.1; andB: up to 0.01;wherein 0.02≤Nb+V+Ti≤0.25 is met, with the remainder being iron and melting-induced impurities.2. The steel material as claimed in claim 1 , wherein the microstructure consists of at least 90 vol. % bainite and the proportions of residual austenite and martensite and ferrite are <10 vol. %.3. The steel material as claimed in claim 2 , wherein with respect to one or more of the following elements the composition is in wt. %:C: 0.02 to 0.11; and/orSi: 0.01 to 0.5; and/orMn: 1.4 to 2.2; and/orAl: 0.015 to 0.1; and/orCr: up to 0.3; and/orNi: up to 0.2; and/orMo: 0.05 to 0.5; and/orB: max. 0.004; and/orwherein 0.05≤Nb+V+Ti≤0.2.4. The steel material as claimed in claim 3 , wherein with respect to the following elements the composition is in wt. % claim 3 , as ...

TUBE BODY THAT IS TO BE USED IN HIGH-TEMPERATURE ATMOSPHERE AND METHOD FOR FORMING METAL OXIDE LAYER ON INNER SURFACE OF TUBE BODY

The present invention provides a tube body that is to be used in a high-temperature atmosphere and a method for stably forming a metal oxide layer on an inner surface of the tube body at a high area percentage. 110-. (canceled)11. A tube body that is to be used in a high-temperature atmosphere ,wherein the tube body is constituted by a heat-resistant alloy containing Cr in an amount of 15 mass % or more and Ni in an amount of 18 mass % or more, andon an inner surface, an arithmetic average roughness (Sa) of three-dimensional surface roughness satisfies 1.5≤Sa≤5.0 and a skewness (Ssk) of a surface height distribution satisfies |Ssk|≤0.30.12. The tube body according to claim 11 ,wherein the heat-resistant alloy contains Al in an amount of 2.0 mass % or more.13. The tube body according to claim 11 ,wherein on the inner surface, a kurtosis (Sku) of a surface height distribution of the three-dimensional surface roughness satisfies Sku≥2.5.14. The tube body according to claim 12 ,wherein on the inner surface, a kurtosis (Sku) of a surface height distribution of the three-dimensional surface roughness satisfies Sku≥2.5.15. The tube body according to claim 11 ,wherein the inner surface is provided with a projection through overlay welding,the projection contains Al in an amount of 2.0 mass % or more, andan arithmetic average roughness (Sa) of three-dimensional surface roughness of the projection satisfies 1.5≤Sa≤5.0 and a skewness (Ssk) of a surface height distribution satisfies |Ssk|≤0.30.16. The tube body according to claim 12 ,wherein the inner surface is provided with a projection through overlay welding,the projection contains Al in an amount of 2.0 mass % or more, andan arithmetic average roughness (Sa) of three-dimensional surface roughness of the projection satisfies 1.5≤Sa≤5.0 and a skewness (Ssk) of a surface height distribution satisfies |Ssk|≤0.30.17. The tube body according to claim 13 ,wherein the inner surface is provided with a projection through overlay ...

Austenitic Stainless Steel

Provided is an austenitic stainless steel having excellent anti-carburizing properties even in a high temperature carburizing environment, and an excellent hot workability in its production. The austenitic stainless steel according to the present embodiment includes a chemical composition consisting of, in mass percent, C: 0.03 to less than 0.25%, Si: 0.01 to 2.0%, Mn: 2.0% or less, Cr: 10 to less than 22%, Ni: more than 30.0% to 40.0%, Al: more than 2.5% to less than 4.5%, Nb: 0.01 to 3.5%, Ca: 0.0005 to 0.05%, Mg: 0.0005 to 0.05%, and N: 0.03% or less, with the balance being Fe and impurities. In the austenitic stainless steel, a Cr concentration Cz,23 n its outer layer and an Al concentration Cn the outer layer satisfy Formula (1) for a Cr concentration Cin an other-than-outer-layer region and an Al concentration Cin the other-than-outer-layer region. 1. An austenitic stainless steel comprising a chemical composition consisting of , in mass percent:C: 0.03 to less than 0.25%;Si: 0.01 to 2.0%;Mn: 2.0% or less;P: 0.04% or less;S: 0.01% or less;Cr: 10 to less than 22%;Ni: more than 30.0% to 40.0%;Al: more than 2.5% to less than 4.5%;Nb: 0.01 to 3.5%;N: 0.03% or less;Ca: 0.0005 to 0.05%;Mg: 0.0005 to 0.05%;Ti: 0 to less than 0.2%;Mo: 0 to 0.5%;W: 0 to 0.5%;Cu: 0 to 0.5%;V: 0 to 0.2%; andB: 0 to 0.01%, {'br': None, 'i': C', 'C', '/C, 'sub': Cr', 'Cr', 'Al, 'img': {'@id': 'CUSTOM-CHARACTER-00033', '@he': '3.22mm', '@wi': '7.79mm', '@file': 'US20190127832A1-20190502-P00002.TIF', '@alt': 'custom-character', '@img-content': 'character', '@img-format': 'tif'}, '0.40≤()≤0.80\u2003\u2003(1)'}, 'with the balance being Fe and impurities, and satisfying Formula (1){'sub': Cr', 'Al', 'Cr', 'Al, 'img': [{'@id': 'CUSTOM-CHARACTER-00034', '@he': '3.56mm', '@wi': '2.12mm', '@file': 'US20190127832A1-20190502-P00001.TIF', '@alt': 'custom-character', '@img-content': 'character', '@img-format': 'tif'}, {'@id': 'CUSTOM-CHARACTER-00035', '@he': '3.22mm', '@wi': '2.46mm', '@file': ' ...

METHOD OF PRODUCING TUBE OF DUPLEX STAINLESS STEEL

Method of producing a tube of duplex stainless steel is disclosed. The steel comprises the following composition, in weight %: C max 0.03, Si max 1.0, Mn max 1.5, P max 0.05, S max 0.03, Cr 24-26, Ni 6-8, Mo 3.0-4.0, N 0.24-0.32. The method comprises steps of: forming a tube of the duplex stainless steel, cold working the tube obtained from the step of forming a tube, and soft annealing the tube after the step of cold working by subjecting the tube to a temperature, T, within a range of 500-750° C. for a time period, t, of 0.5-5 minutes. 2. (canceled)3. The method according to claim 1 , wherein the step of soft annealing the tube comprises subjecting the tube to a temperature within a range of 600-750° C. for a time period of 1-3 minutes.4. The method according to claim 1 , wherein the step of soft annealing the tube is followed by a step of:quenching the tube.5. The method according to claim 1 , wherein the step of cold working the tube claim 1 , includes an area reduction of the tube within a range of 25-70%.6. The method according to claim 1 , wherein the step of forming a tube comprises steps of:producing an ingot or a continuous casted billet of the duplex stainless steel, andhot extruding the ingot or the billet obtained from the step of producing an ingot or a continuous casted billet into the tube.7. The method according to claim 1 , wherein the step of forming a tube comprises steps of:providing a melt of the duplex stainless steel,atomizing the melt of the duplex stainless steel to produce a powder of the duplex stainless steel,forming the tube of the powder of the duplex stainless steel in a process that includes hot isostatic pressing the powder of duplex stainless steel.8. The method according to claim 1 , wherein the target minimum yield strength claim 1 , Rp0.2 claim 1 , of the duplex stainless steel is 868.25-1156.25 MPa with a standard deviation of 10 MPa.9. The method according to claim 1 , wherein the amount of Mn in the composition is 0 to 1.2 wt ...

LOW ALLOY STEEL FOR OIL COUNTRY TUBULAR GOODS HAVING EXCELLENT SULFIDE STRESS CRACKING RESISTANCE AND MANUFACTURING METHOD THEREFOR

The low alloy steel for oil country tubular goods according to the present invention has a chemical composition containing, by mass percent, C: 0.56 to 1.00%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: at most 0.025%, 5: at most 0.010%, Al: 0.005 to 0.100%, Mo: 0.40 to 1.00%, V: 0.05 to 0.30%, and O: at most 0.010%, the balance being Fe and impurities, wherein the yield stress thereof is at least 862 MPa, and the half-value width of a [211] crystal surface obtained by X-ray diffraction is at most 0.50°. 115-. (canceled)16. A low alloy steel for oil country tubular goods having a chemical composition containing , by mass percent ,C: 0.56 to 1.00%,Si: 0.05 to 0.50%,Mn: 0.05 to 1.00%,P: at most 0.025%,S: at most 0.010%,Al: 0.005 to 0.100%,Mo: 0.40 to 1.00%,V: 0.07 to 0.30%,O: at most 0.010%, andN: at most 0.0300%,the balance being Fe and impurities, whereinthe yield stress thereof is at least 862 MPa; andthe half-value width of a [211] crystal surface obtained by X-ray diffraction is at most 0.50°.17. The low alloy steel for oil country tubular goods according to claim 16 , wherein the chemical composition contains Cr: at most 2.00% in place of some of Fe.18. The low alloy steel for oil country tubular goods according to claim16 claim 16 , wherein the chemical composition contains claim 16 , in place of some of Fe claim 16 ,one or more selected from a group consisting ofNb: at most 0.100%,Ti: at most 0.100%, andZr: at most 0.100%.19. The low alloy steel for oil country tubular goods according to claim 17 , wherein the chemical composition contains claim 17 , in place of some of Fe claim 17 ,one or more selected from a group consisting ofNb: at most 0.100%,Ti: at most 0.100%, andZr: at most 0.100%.20. The low alloy steel for oil country tubular goods according to claim 16 , wherein the chemical composition contains Ca: at most 0.0100% in place of some of Fe.21. The low alloy steel for oil country tubular goods according to claim 17 , wherein the chemical composition ...