ГИБКАЯ ТРУБА С ПЕРЕМЕННЫМИ МЕХАНИЧЕСКИМИ СВОЙСТВАМИ И СПОСОБ ЕЕ ИЗГОТОВЛЕНИЯ НЕПРЕРЫВНОЙ ТЕРМООБРАБОТКОЙ

Описаны гибкие трубы в бухтах с улучшенными и переменными свойствами по длине трубы, производимые при помощи процесса непрерывной динамической термообработки (НДТО). Гибкие трубы разматывают с барабана, подвергают процессу НДТО и снова наматывают на барабан. С помощью процесса НДТО можно осуществлять производство «композитных» труб таким образом, чтобы селективно изменять свойства трубы по ее длине. Например, свойства трубы можно селективно задавать по длине специально для технологического процесса, в котором будет применяться труба. Технический результат - изменение механических свойств участков гибкой трубы по всей длине. 3 н. и 20 з.п. ф-лы, 6 ил., 2 табл., 4 пр.

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.

ВЫСОКОПРОЧНЫЕ ТОЛСТОСТЕННЫЕ СТАЛЬНЫЕ ТРУБЫ, СВАРЕННЫЕ ЭЛЕКТРИЧЕСКОЙ КОНТАКТНОЙ СВАРКОЙ, С ВЫСОКОЙ УДАРНОЙ ВЯЗКОСТЬЮ И СПОСОБ ИХ ИЗГОТОВЛЕНИЯ

Изобретение относится к области металлургии, а именно к толстостенным стальным трубам, которые могут быть использованы для бурения или транспортировки нефти и природного газа. Высокопрочная толстостенная стальная труба, сваренная электрической контактной сваркой, содержит, мас.%: С 0,025-0,084, Si 0,10-0,30, Mn 0,70-1,80, P 0,001-0,018, S 0,0001-0,0029, Al 0,01-0,10, Nb 0,001-0,065, V 0,001-0,065, Ti 0,001-0,033, Са 0,0001-0,0035, N 0,0050 или менее, О 0,0030 или менее, при необходимости по меньшей мере один элемент, выбранный из: В 0,0030 или менее, Cu 0,001-0,350, Ni 0,001-0,350, Mo 0,001-0,350 и Cr 0,001-0,700, Fe и случайные примеси - остальное. Параметр Pcm, характеризующий микроструктуру после быстрого охлаждения сварного шва трубы и определяемый выражением Pcm=C+Si/30+Mn/20+Cu/20+Ni/60+Cr/20+Mo/15+V/10+5·B, равен 0,20 или менее. Микроструктура включает 90% по площади или более квазиполигонального феррита, имеющего размер зерна 10 мкм или менее в основной части стальной трубы и в ...

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

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

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 ...

УЛЬТРАВЫСОКОПРОЧНЫЙ СПЛАВ ДЛЯ ЖЕСТКИХ УСЛОВИЙ ДОБЫЧИ НЕФТИ И ГАЗА И СПОСОБ ЕГО ПОЛУЧЕНИЯ

... 1. Высокопрочный, коррозионно-стойкий сплав, подходящий для применения в нефтяных и газовых средах, содержащий, в вес.%: 0-15% Fe, 18-24% Cr, 3-9% Mo, 0,05-3,0% Cu, 3,6-6,5% Nb, 0,5-2,2% Ti, 0,05-1,0% Al, 0,005-0,040% С, остальное Ni плюс случайные примеси и раскислители. ! 2. Сплав по п.1, причем содержание Ni составляет 35-70%. ! 3. Сплав по п.1, причем содержание Ni составляет 40-65%. ! 4. Сплав по п.1, причем содержание Ni составляет 50-60%. ! 5. Прутки или трубы, подходящие для применения в нефтяных/газовых скважинах с агрессивной средой, выполненные из сплава по п.1. ! 6. Сплав по п.1, имеющий 5-15% Fe, 18-23% Cr, 3,0-7,5% Mo, 0,1-3,0% Cu, 3,6-6,0% Nb, 0,6-2,1% Ti, 0,1-1,0% Al и 0,005-0,030% С. ! 7. Сплав по п.1, содержащий 6-12% Fe, 19-22% Cr, 3,5-7,5% Mo, 1,0-3,0% Cu, 4,0-6,0% Nb, 0,8-2,0% Ti, 0,1-0,7% Al, 0,005-0,020% С, остальное Ni плюс случайные примеси и раскислители. ! 8. Сплав по п.1, причем отношение Nb/(Ti+Al)=2,5-7,5 с тем, чтобы обеспечить желательную для высокой прочности ...

МАРТЕНСИТНАЯ ХРОМСОДЕРЖАЩАЯ СТАЛЬ И ТРУБЫ, ПРИМЕНЯЕМЫЕ В НЕФТЯНОЙ ПРОМЫШЛЕННОСТИ

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

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

БЕСШОВНАЯ ТРУБКА ИЛИ ТРУБА ИЗ ВЫСОКОПРОЧНОЙ НЕРЖАВЕЮЩЕЙ СТАЛИ ДЛЯ ТРУБНЫХ ИЗДЕЛИЙ НЕФТЕГАЗОПРОМЫСЛОВОГО СОРТАМЕНТА И СПОСОБ ЕЕ ИЗГОТОВЛЕНИЯ

ТОЛСТОСТЕННАЯ СТАЛЬНАЯ ТРУБА ДЛЯ НЕФТЯНЫХ СКВАЖИН И СПОСОБ ЕЕ ПРОИЗВОДСТВА

УСТРОЙСТВО ДЛЯ ТЕРМИЧЕСКОЙ ОБРАБОТКИ МЕТАЛЛИЧЕСКОГО ЭЛЕМЕНТА В ВИДЕ ТРУБЫ ИЛИ СТЕРЖНЯ, ИМЕЮЩЕГО КРИВОЛИНЕЙНЫЕ УЧАСТКИ

Устройство для быстрого охлаждения горячих металлических труб

... 1. УСТРОЙСТВО ДЛЯ БЫСТРОГО ОХЛАВДЕНИЯ ГОРЯЧИХ МЕТАЛЛИЧЕСКИХ ТРУБ, содержащее закалочный бак, транспортное средство для загрузкивыгрузки труб и средство перемещения в баке, выполненное в виде по меньшей мере одной пары двупле.чих рычагов , закрепленных на одной оси с возможностью поворота, при этом одно из плеч имеет захват для удержания изделий, отличающееся тем, что, с целью повышения равномерности охлаждения труб путем симметричной циркуляции охлаждающей жидкости вокруг трубы в процессе опускания в бак, устройство снабжено отражателем, расположенным вдоль бака на плечах с захватами ниже уровня захватов, и системой газоподвода с соплом, установленным на одS ном конце бака с возможностью подачи (Л воздуха.непосредственно в полость трубы в процессе погружения в бак и выдержки в нем. со о со со 4 ...

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.

Verfahren zur Erzielung hoher Guetewerte bei gegossenen Hohlkoerpern oder mit Hohlraeumen ausgestatteten Gussstuecken aus Stahl oder Stahllegierungen

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.

Kühlvorrichtung für nahtlose Stahlrohre

Kühlvorrichtung (1) zum Abkühlen eines nahtlosen, gewalzten Rohrs (R) aus einem Metall, vorzugsweise Stahl, die eine Düsenanordnung (10) mit einer oder mehreren Düsen (14) aufweist, die eingerichtet sind, um die Außenumfangsfläche des Rohrs (R) mit einem Kühlmedium (K), vorzugsweise Wasser oder einem Wassergemisch, zu beaufschlagen, während das Rohr (R) entlang einer Förderrichtung (F) durch eine Kühlstrecke der Kühlvorrichtung (1) transportiert wird, wobei die Düsenanordnung (10) einen Zugang (Z) aufweist, über den das Rohr (R) in radialer Richtung des Rohrs (R), vorzugsweise nach oben, aus der Kühlstrecke herausnehmbar ist.

Internal hardening of tubing - by immersion in a quenching bath and internally flowing coolant applicationt application

The tubes are quenched in such a way that the rate of coolant flow through the tube is greater than the rate of immersion into the quenching bath. The coolant is directed at the internal walls of the tubing and thus achieves the super critical cooling rate necessary for the formation of martensitic structures on the inner surfaces. The rate of heat removal is thus faster on the inner surfaces than the outer.

Multi-pipe type quenching apparatus

A multi-pipe quenching apparatus for simultaneously quenching a plurality of steel pipes at a high speed. The apparatus comprises (a) a steel pipe holding table for holding a plurality of steel pipes arranged in parallel which table is provided with a plurality of sets each including a plurality of clamp means for clamping a steel pipe at a plurality of points in the lengthwise direction thereof, and cooling water supply means for supplying water into said pipe through a nozzle pressed thereagainst, and (b) a quenching tank capable of containing water up to a predetermined level as occasion demands; whereby the holding table is vertically moved into and out of the quenching tank and the supply of water into the steel pipes is controlled by the cooling water supply means thereby quenching the steel pipes.

Quenching method and apparatus for steel pipes

A quenching method and apparatus for quenching a steel pipe heated throughout the length thereof to a given quenching temperature in which during cooling of the steel pipe, the pipe is rotated or the pipe is moved axially while rotating it thereby uniformly cooling the entire pipe. The apparatus is incorporated as an in-line equipment in a steel pipe production line whereby a steel pipe introduced from the preceding processing stage is quenched by the said quenching method and is then delivered automatically to the following processing stage thereby uniformly cooling the steel pipe in the lengthwise direction thereof and reducing the quenching time.

METHOD AND APPARATUS FOR COOLING INNER SURFACE OF METAL PIPE

... 1529664 Spray-producers NIPPON KOKAN KK 26 Jan 1977 3128/77 Heading B2F [Also in Division C7] A metal pipe is quenched internally by relative motion between it and an annular cooling head 2 having peripheral nozzles 4 which discharge jets of liquid or mixed liquid-gaseous coolant inclined at an angle (d) of 30-70‹ to the radial plane of the head in the direction in which the pipe is moving, and at an angle (#) of .30-90‹ to the radii of the head, whereby the coolant flows along the tube bore in a helical path away from the hot region. The coolant leaves the nozzles at >5 m/sec, and is preferably either water or a water-air mixture.

IMMERSION COOLING METHOD FOR HOT METAL PIPES

PROCEDURE AND DEVICE FOR SNAPPING COOLING OF WORKPIECES

PROCEDURE FOR THE TRANSFORMATION OF STEEL BLANKS

DEVICE AND PROCEDURE FOR FORMING AND DETERRING A CARRIER

DEVICE FOR SNAPPING COOLING OF METALLIC PIPES.

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 ...

Stainless steel for oil well, stainless steel pipe for oil well, and process for production of stainless steel for oil well

Disclosed is a stainless steel having the following chemical composition: C: 0.05% or less, Si: 0.5% or less, Mn: 0.01 to 0.5%, P: 0.04% or less, S: 0.01% or less, Cr: more than 16.0% and not more than 18.0%, Ni: more than 4.0% and not more than 5.6%, Mo: 1.6 to 4.0%, Cu: 1.5 to 3.0%, Al: 0.001 to 0.10%, and N: 0.050% or less, with the remainder being Fe and impurities, wherein the components meet the requirements represented by formulae (1) and (2). The structure of the stainless steel contains a martensite phase and 10 to 40% by volume of a ferrite phase, wherein the percentage of distribution of the ferrite phase is greater than 85%. Cr + Cu + Ni + Mo 25.5 (1) -8 30(C+N) + 0.5Mn + Ni + Cu/2 + 8.2 - 1.1(Cr+Mo) -4 (2) ...

Method for producing seamless steel pipe

Disclosed is a method for producing a seamless steel pipe, comprising subjecting a billet having a component composition of, in terms of mass%, C (0.15 to 0.35%), Si (0.05 to 0.5%), Mn (0.1 to 1.5%), Cr (0.2 to 1.5%), Mo (0.1 to 1.5%), Ti (0.005 to 0.50%), Al (0.001 to 0.50%), and as the remainder, Fe and impurities in which the content of Ni is 0.1% or less, the content of P is 0.04% or less, the content of S is 0.01% or less, the content of N is 0.01% or less, and the content of O is 0.01% or less to hot-piercing and hot-rolling, and further performing a heating treatment, wherein direct quenching is performed from when the temperature of a steel pipe after hot-rolling is not lower than an Ar ...

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 ...

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 ...

MARTENSITIC STAINLESS STEEL TUBE AND MANUFACTURING METHOD THEREOF

A martensitic stainless steel pipe wherein it has a chemical composition in which the contents of C, Si, Mn and Cr are respectively limited to specific ranges, and wherein the scale formed on the outer surface of the pipe has a porosity in a specific range depending on the thickness thereof. The steel pipe can exhibit an improved accuracy in the detection of defects by a non- destructive inspection such as ultrasonic flaw detection, which results in the improved efficiency in the non-destructive inspection, and is also advantageous in that it has improved atmosphere corrosion resistance. Accordingly, the above steel pipe and a method for production thereof can be suitably utilized in all the applications wherein use is made of a martensitic stainless steel pipe having a chemical composition equivalent to the above.

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.

MULTI-PIPE TYPE QUENCHING APPARATUS

A multi-pipe quenching apparatus for simultaneously quenching a plurality of steel pipes at a high speed. The apparatus comprises (a) a steel pipe holding table for holding a plurality of steel pipes arranged in parallel which table is provided with a plurality of sets each including a plurality of clamp means for clamping a steel pipe at a plurality of points in the lengthwise direction thereof, and cooling water supply means for supplying water into said pipe through a nozzle pressed thereagainst, and (b) a quenching tank capable of containing water up to a predetermined level as occasion demands; whereby the holding table is vertically moved into and out of the quenching tank and the supply of water into the steel pipes is controlled by the cooling water supply means thereby quenching the steel pipes.

METHOD AND APPARATUS FOR HEAT TREATING STEEL

A process is provided for heat treating steel in which each segment of a piece of steel is quenched in a quenching zone by directing the flow of a sufficient amount of a cooling medium against a surface of each segment to lower the temperature of the segment to a desired temperature while vaporizing substantially all of the cooling medium to create a vapor blanket around at least one surface of each segment so cooled. In one embodiment, steel pipe is heated above its critical transformation temperature and then each longitudinal segment of the pipe is sequentially quenched by substantially simultaneously sending a sufficient amount of water against the inside and outside surfaces of each segment to reduce the temperature of the segment to within a predetermined range while vaporizing substantially all of the water to create a steam blanket around the segment. The steam blanket is then maintained on at least the inside surface of each segment in order to control the temperature change of ...

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.

ELECTRIC RESISTANCE WELDED CLAD STEEL PIPE OR TUBE AND METHOD OF PRODUCING SAME

Provided is an electric-resistance-welded clad steel pipe whereby a region in which a solidification structure having a particularly large effect on characteristics is formed in a weld is reduced, and function as a clad pipe is also not compromised. An electric-resistance-welded clad steel pipe having a first layer comprising carbon steel or low-alloy steel as a base metal and a cladding metal second layer comprising stainless steel or a nickel-containing alloy, the second layer being layered on one surface of the first layer, wherein the base metal is not exposed on a cladding-metal-side surface of the electric-resistance-welded clad steel pipe in a weld, and a solidification structure is not contained in each of circular cross-sections having a radius of 0.1 mm in a plane perpendicular to the pipe longitudinal direction, the circular cross-sections being centered at positions (i) through (iii). (i): A position in the weld at a depth of 1 mm from the outer surface of the electric-resistance-welded ...

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 ...

HOLLOW STABILIZER

A hollow stabilizer has a tubular shape and is provided with: a torsion section that is provided to a vehicle and that extends in the vehicle width direction; an arm section that extends in the front-back direction of the vehicle; and bent sections that connect the torsion section and the arm section. The hollow stabilizer is characterized in that the hardness of the outer surface of the bent inner sides of the bent sections is 70% or more with respect to the hardness of the outer surface of the arm section.

OIL-WELL STEEL PIPE HAVING EXCELLENT SULFIDE STRESS CRACKING RESISTANCE

Provided is a steel oil well pipe which has excellent sulfide stress cracking resistance (SSC resistance). A steel oil well pipe of the present invention contains, in mass%, 0.15-0.35% of C, 0.1-0.75% of Si, 0.1-1.0% of Mn, 0.1-1.7% of Cr, 0.1-1.2% of Mo, 0.01-0.05% of Ti, 0.010-0.030% of Nb, 0.01-0.1% of Al, 0.03% or less of P, 0.01% or less of S, 0.007% or less of N and 0.01% or less of O, with the balance made up of Fe and impurities. The Ti content and the Nb content in the residue obtained by bromine-methanol extraction satisfy the following formula (1). 100 × [Nb]/([Ti] + [Nb]) = 27.5 (1) In this connection, the Ti content (mass%) and the Nb content (mass%) in the residue are respectively assigned to [Ti] and [Nb].

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.

METHOD FOR MANUFACTURING SEAMLESS PIPES

Disclosed is a method for producing a seamless steel pipe, comprising subjecting a billet having a component composition of, in terms of mass%, C (0.15 to 0.35%), Si (0.05 to 0.5%), Mn (0.1 to 1.5%), Cr (0.2 to 1.5%), Mo (0.1 to 1.5%), Ti (0.005 to 0.50%), Al (0.001 to 0.50%), and as the remainder, Fe and impurities in which the content of Ni is 0.1% or less, the content of P is 0.04% or less, the content of S is 0.01% or less, the content of N is 0.01% or less, and the content of O is 0.01% or less to hot-piercing and hot-rolling, and further performing a heating treatment, wherein direct quenching is performed from when the temperature of a steel pipe after hot-rolling is not lower than an Ar3 transformation point and thereafter the heating treatment is performed at a temperature of 450°C or higher but not higher than an Ac1 transformation point in heating treatment equipment provided in connection with a quenching device which performs the direct quenching, further the steel pipe having ...

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°.

A Device for Tempering Steel Tubes

Appts. for cooling heat treated components

The appts. for cooling heat-treated material, such as thick-walled steel piping, has ring units (18) for the coolant distribution channels (30) from the coolant distribution zone (28) laid in the housing (12) at least partially shrouding the coolant distribution zone (28).

SPINNING PIPES FROM CORROSION-RESISTANT ALLOYS AND PIPE, MADE WITH ITS USE

СПОСОБ И УСТРОЙСТВО ДЛЯ ПРОИЗВОДСТВА СТАЛЬНЫХ ТРУБ

Изобретение относится к способу производства стальных труб и устройству для осуществления этого способа. В соответствии с этим изобретением, в течение промежутка времени не более чем 20 секунд после последней деформации при температуре более 700 ºС, или не менее 1050 ºС, во время прохождения на внешнюю поверхность трубы длиной, которая более чем в 400 раз превышает толщину ее стенки, подают хладагент под повышенным давлением в количестве, которая во время быстрого охлаждения обеспечивает однородную скорость охлаждения стенки трубы по всей ее длине более 1 ºС/с до температуры в диапазоне от 500 до 250 ºС, после чего дальнейшее охлаждение трубы до комнатной температуры выполняют на воздухе.

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 A QUENCHED AND TEMPERED SEAMLESSLY HOT-FABRICATED STEEL PIPE

LOW-ALLOY STEEL PIPE FOR OIL WELL AND PRODUCTION METHOD THEREFOR

INDUCTION HEATING COIL, AND AN APPARATUS AND METHOD FOR MANUFACTURING A WORKED MEMBER

HIGH CHROMIUM MARTENSITE HEAT-RESISTANT STEEL, CHARACTERISED BY HIGH LONG-TERM STRENGTH AND OXIDATION RESISTANCE

METHOD AND APPARATUS FOR PRODUCING STEEL PIPES

OIL-WELL STEEL PIPE HAVING EXCELLENT SULFIDE STRESS CRACKING RESISTANCE

Electric self-heating quenching device

Quench-hardening of pipes

Surface hardening the bores of pipe elbows - using burner segments mounted on adjustable carriers so burner dia. can be varied

FAST COOLER OF METAL TUBES

성형장치 및 성형방법

... 적절한 특성을 갖는 성형품을 얻을 수 있는 성형장치 및 성형방법을 제공한다. 제어부(70)는, 블로성형금형(13)에 의한 성형완료 이후에, 블로성형금형(13)을 개방하도록 당해 블로성형금형(13)의 동작을 제어하고, 냉각매체를 금속파이프(80)에 접촉시키도록 냉각부(90)를 제어함으로써, 냉각매체에 의한 금속파이프(80)의 냉각을 행한다. 이와 같이, 냉각매체를 접촉시켜 냉각을 행함으로써, 블로성형금형(13)을 접촉시키는 것에 의한 냉각에 비하여, 냉각속도를 늦출 수 있어, 금속파이프(80)의 인성을 높이는 담금질이 가능해진다. 또, 냉각매체를 이용하여 냉각하는 경우는, 냉각매체를 접촉시키는 시간, 냉각매체의 양, 냉각매체의 온도 등을 조정함으로써, 금형을 접촉시키는 것에 의한 냉각에 비하여, 담금질성의 조정을 용이하게 행할 수 있다.

Heat processing system and heat processing method

tubo de aço sem costura, método de fabricação de um tubo de aço sem costura

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 ...

A SEAMLESS STEEL TUBE FOR WORK-OVER RISER AND METHOD OF MANUFACTURING

The present invention relates to seamless steel tubing for conditioning risers, said tubing comprising, in percentage by weight, 0.23-0.29 carbon, 0.45-0.65 manganese, 0.15-0.35 silicon, 0.90-1.20 chromium, 0.70-0.90 molybdenum, maximum 0.20 nickel, maximum 0.010 nitrogen, 0.0010-0.0030 boron, 0.010-0.045 aluminium, maximum 0.005 sulphur, maximum 0.015 phosphorus, 0.005-0.030 titanium, 0.020-0.035 niobium, maximum 0.15 copper, maximum 0.20 arsenic, maximum 0.0040 calcium, maximum 0.020 tin, maximum 2.4 ppm hydrogen, the remainder being iron and inevitable impurities. The geometry of the pipe is such that the ends thereof have increasing wall thickness and outer diameter, and the pipe has an elasticity limit of at least 620 MPa (90 ksi) throughout the length of the pipe body and at the pipe ends. The present invention also relates to methods for producing seamless steel piping for conditioning risers having an elasticity limit of at least 620 MPa (90 ksi) both in the pipe body and at the ...

AUTOMATIC PIPE QUENCHING APPARATUS

The present invention relates to the automatic pipe quenching apparatus consisting of a transfer system (D) for the transfer of the pipe discharged from furnace to a supporting rolls bed (E) driven in a rotation motion for the rotation of the pipe (X), a cooling system with outside under pressure water jets (H), a cooling system by dipping water tank (I), a cooling system with inside under pressure water jets (J), a water filtration and scale holding system (K), an automation system for the whole process with programmable automat to which the variable rotation speed of the pipe is made by a hydraulic system (F) driven by a hydraulic motor (17), the pipe cooling with variable speeds being made by a pipe (32) with cooling orifices (a) with outside under pressure water jets, to which the water discharge and pressure are controlled by a setting sluice gate (47) and by the ratio between the orifices (a) surface to inside surface of the pipe with orifices griped in some seals (33) with help of ...

HIGH-STRENGTH STAINLESS STEEL SEAMLESS PIPE FOR USE AS OIL WELL PIPING, AND MANUFACTURING METHOD THEREFOR

Provided is a high-strength stainless steel seamless pipe for use as oil well piping that has a wall thickness surpassing 25.4 mm, that is rated at 110 ksi (758 MPa) or higher, that exhibits a vE-10 of 40J or higher, and that exhibits excellent corrosion resistance in a high-temperature corrosive environment. The steel seamless pipe is obtained by heating and hot rolling a steel material of which the composition includes, in terms of mass%, 0.005-0.06% of C, 0.05-0.5% of Si, 0.2-1.8% of Mn, 15.5-18.0% of Cr, 1.5-5.0% of Ni, 0.02-0.2% of V, 0.002-0.05% of Al, 0.01-0.15% of N, and 0.006% or less of O, and additionally includes 1.0-3.5% of Mo and/or 3.0% or less of W and/or 3.5% or less of Cu so as to satisfy [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]. On this occasion, hot rolling is carried out so as to achieve a total rolling reduction rate of 30% or more in the temperature range of 1100-900° C. After completion ...

STEEL PIPE FOR USE AS EMBEDDED EXPANDED PIPE, AND METHOD OF EMBEDDING OIL-WELL STEEL PIPE

... (1) A steel pipe to be expanded in a state in which it is inserted in a well, such as an oil well, characterized in that the wall thickness eccentricity EO(%) prior to pipe expansion satisfies the following formula 1: EO ≤ 30 / (1 + 0.018 a) ...1 where α is the pipe expansion percentage (%) calculated from the following formula 2. α = [(inner diameter of pipe subsequent to pipe expansion inner diameter of pipe prior to pipe expansion) / inner diameter of pipe prior to pipe expansion] x 100 ...2. (2) A steel pipe to be expanded in a state in which it is inserted in a well, characterized in that the wall thickness eccentricity is not more than 10%. If a pipe embedding and expanding method is embodied using the steel pipe described in (1) or (2) above, the expanded steel pipe is prevented from having its crushing strength decreased, and the bending of the steel pipe is reduced.

SYSTEMS AND METHODS FOR PRODUCING HOT INDUCTION PIPE BENDS WITH HOMOGENEOUS METALLURGICAL AND MECHANICAL PROPERTIES

A system is provided for manufacturing a pipe bend, including: a securement structure including a securement device configured to secure a first end of a pipe and a pivot arm coupled to the securement device and configured to pivot about a pivot point to introduce a bend in the pipe; an induction ring configured to heat an annular band of a wall of the pipe; a first quenching ring configured to direct a first quenching fluid toward an outer surface of the heated annular band in the wall of the pipe; a second quenching ring configured to direct a second quenching fluid toward an inner surface of the heated annular band in the wall of the pipe; and a processor configured to control release of the first quenching fluid and the second quenching fluid such that the first quenching fluid reaches the outer surface and the second quenching fluid reaches the inner surface substantially concurrently.

Multi-pipe type quenching apparatus

A multi-pipe quenching apparatus for simultaneously quenching a plurality of steel pipes at a high speed. The apparatus comprises (a) a steel pipe holding table for holding a plurality of steel pipes arranged in parallel which table is provided with a plurality of sets each including a plurality of clamp means for clamping a steel pipe at a plurality of points in the lengthwise direction thereof, and cooling water supply means for supplying water into said pipe through a nozzle pressed thereagainst, and (b) a quenching tank capable of containing water up to a predetermined level as occasion demands; whereby the holding table is vertically moved into and out of the quenching tank and the supply of water into the steel pipes is controlled by the cooling water supply means thereby quenching the steel pipes.

Track bushing and method and apparatus for producing the same

Quenched layers are formed without irregularities on the inner circumferential surface of a track bushing having a small inside diameter or on the inner circumferential surfaces of two or more track bushings which are subjected to quenching in an overlapped condition. To introduce a cooling medium for cooling the inner circumferential surface of the track bushing, a guide tube having an outside diameter smaller than the inside diameter of the track bushing is disposed on the side of the inner circumferential surface and the cooling medium introduced by the guide tube is diverted by a diverting member having a spherical or similar curved surface, such that the cooling medium is allowed to flow in a direction substantially parallel with an axial direction of the track bushing 1 within a space defined by the outer circumferential surface of the guide tube and the inner circumferential surface of the track bushing, thereby performing laminar flow cooling.

Method and Apparatus for Producing Steel Pipes Having Particular Properties

The invention relates to a method and to an apparatus for producing pipes made of steel. According to the invention, within a period of time of no more than 20 seconds after the last deformation at a temperature greater than 700° C., but less than 1050° C., during passage a cooling medium is applied with elevated pressure onto the outside circumference of the pipe over a length of greater than 400 times the pipe wall thickness in a quantity which during rapid cooling provides an equivalent cooling speed of greater than 1° C./second of the pipe wall over the pipe length to a temperature in the range of 500° C. to 250° C., whereupon further cooling of the pipe down to room temperature is carried out by exposure to air.

WELLBORE TUBULAR AIR QUENCHING

A system for air quenching a heat treated element comprises a tubular component, an internal air quench device moveably disposed within the interior of the tubular component, and an external air quench device moveably disposed about the tubular component. The internal air quench device comprises a nozzle configured to induce an airflow within the tubular component. The external air quenching device can comprise an annular ring disposed about the tubular component that is configured to generate a cone of air about the tubular component. 1. A system for air quenching a heat treated element , the system comprising:a tubular component;an internal air quench device moveably disposed within the interior of the tubular component, wherein the internal air quench device comprises a nozzle configured to convert compressed air into a jet of air within the tubular component and induce an airflow within the tubular component, wherein the nozzle is configured to emit the jet of air along a longitudinal axis of the tubular component with an outward deflection from the longitudinal axis of between 0 and 45 degrees; andan external air quench device disposed about the tubular component and moveable relative to the tubular component.2. The system of claim 1 , further comprising an induction coil disposed about the tubular component claim 1 , wherein the induction coil is configured to heat the tubular and create a heat affected zone.3. The system of claim 2 , wherein the heat affected zone includes a weld line between two tubulars.4. The system of claim 1 , wherein the tubular component comprises a drill pipe claim 1 , a drill collar claim 1 , a production pipe claim 1 , a tool joint claim 1 , or a downhole tool housing.5. The system of claim 1 , further comprising a compressed air source claim 1 , wherein the nozzle and the external air quench device are in fluid communication with the compressed air source.6. The system of claim 1 , wherein the tubular comprises a heat affected zone ...

HIGH-STRENGTH SEAMLESS STEEL PIPE FOR OIL COUNTRY TUBULAR GOODS AND METHOD OF PRODUCING THE SAME (AS AMENDED)

Provided is a high-strength seamless steel pipe having the composition which contains, by mass %, 0.20 to 0.50% C, 0.05 to 0.40% Si, 0.3 to 0.9% Mn, 0.015% or less P, 0.005% or less S, 0.005 to 0.1% Al, 0.008% or less N, 0.6 to 1.7% Cr, 0.4 to 1.0% Mo, 0.01 to 0.30% V, 0.01 to 0.06% Nb, 0.0003 to 0.0030% B, and 0.0030% or less O (oxygen). The high-strength seamless steel pipe has the microstructure where a volume fraction of a tempered martensitic phase is 95% or more, and prior austenitic grains have a grain size number of 8.5 or more, and a segregation degree index Ps which is defined by a formula Ps=8.1 (XSi+XMn+XMo)+1.2XP relating to XM which is a ratio between a segregated portion content and an average content is set to less than 65.

METHOD FOR TRANSFORMING STEEL BLANKS

APPARATUS FOR DIP-HARDENING METAL PIPE

A hardening apparatus is constructed so that a heated metal pipe is rotatably retained by retaining means so that it is pressed thereby from both above and below. The metal pipe is dipped into cooling water within a water tank by dipping means, and in addition, jets of cooling water are applied to both the inner and outer peripheral surfaces of the metal pipe by cooling water spraying means. After being rapidly cooled in this way, the metal pipe is transported out of the water tank by a transport means. In this apparatus, the metal pipe is not dropped from a height, so it is possible to prevent the surface of the metal pipe becoming flawed, and the rotation of the metal pipe makes it possible to promote what is effectively a stirring of the cooling water. It is also possible to constantly change the portions of the retaining means in contact with the metal pipe, so that the metal pipe can be rapidly and uniformly cooled, and therefore can be well hardened.

HIGH STRENGTH SEAMLESS STAINLESS STEEL PIPE FOR OIL WELLS AND MANUFACTURING METHOD THEREFOR

STEEL TUBE AND METHOD FOR PRODUCING A STEEL TUBE

Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung eines Stahlrohres umfassend die Schritte: - Bereitstellen eines luftgehärteten Ausgangsrohrs, wobei das Ausgangsrohr aus einer Stahllegierung besteht, die - in Massenprozent - aus den folgenden Legierungselementen besteht: TIFF 00000001.tif 133 36 Rest: Eisen und unvermeidbare erschmelzungsbedingte Verunreinigungen, wobei das Verhältnis Ti/N zumindest 3,4 beträgt und die Summe der Gehalte der Legierungselemente Mn+Ni im Bereich zwischen 3% und 6 Ma% liegt, - Erwärmen des Ausgangsrohres auf eine erste Temperatur zwischen 630 und 760°C innerhalb von maximal 60 Minuten, - Halten der ersten Temperatur für 10-90 Minuten und - anschließendes Abkühlen auf Raumtemperatur. Zudem wird ein Stahlrohr offenbart.

サワー環境で使用されるラインパイプ用継目無鋼管

Improved methods for quenching metal tubes

A method of manufacturing a metal tube 10 comprising an open end 11 and an opposing closed end 12 includes heat treating the tube at an elevated temperature, rapidly cooling the tube by immersion in a cooling liquid 20 to at least partially fill the tube with the liquid and develop an evolved gas inside the tube, raising the open end to an elevated position to release at least some of the gas via the open end and lowering the open end to a downward facing position to drain cooling liquid via the open end. The cooling liquid is preferably a quenching liquid and may be water and carbon dioxide, water and a polymer, an oil or an organic aqueous polymer. The tube may comprise a nickel, cobalt steel, aluminium or titanium alloy. The raising of the open end of the tube may be performed using a tiltable device 30 and the tube and the tiltable device may be removed from the liquid prior to lowering the open end of the tube using the tiltable device.

A tubular expansion device with lubricating coatings

An expansion device 4800, such as a cone for radially expanding and plastically deforming an expandable tubular downhole, includes a textured external surface 4802 having a self lubricating relatively hard coating 4804 of lubricant. A self lubricating relatively soft coating/film grease and/or lubricated mud 4806 may also be applied onto the external surface 4802, alone, or in combination with the lubricating hard coating 4804. The lubricant coatings 4804 and 4806 may result in a friction coefficient of not more than 0.05. The lubricant coating 4806 may withstand abrasive and corrosive environments, while the lubricant 4804 may withstand multiple expansions and abrasive and corrosive environments.

Expandable tubular

Improvements in or relating to quenching method and apparatus

... 538,364. Heat treatment of metals; spray nozzles. BUDD INDUCTION HEATING. Inc. Jan. 3, 1940, No. 201. Convention date, Jan. 11, 1939, [Class 72] [Also in Group XXIX] The internal surfaces of cylindrical bodies which may be heated by the method described in Specification 503,130 are quenched by impinging thereon a plurality of substantially radially directed streams of quenching fluid so arranged that the centre of impingement of each stream at the surface is equally spaced axially and circumferentially from the centre of impingement of each adjacent stream. Fig. 1 shows a nozzle for this purpose comprising a tube 10 having a plurality of ports 24 arranged in circular bends 26 uniformly spaced along the length of the nozzle. The bands are situated in annular grooves 40 the walls 42 of which are coned to guide fluid into the jets 24. A central pin 12 formed in steps effects equal distribution of the fluid to the bands 26.

QUENCHING METHOD AND APPARATUS FOR STEEL PIPES

DEVICE AND PROCEDURE FOR DETERRING FROM THIN-WALLED HOLLOW METAL HOUSING

PROCEDURE FOR HARDENING A HOLLOW BODY.

DEVICE FOR THE PRODUCTION OF A WASSERVORHANGS.

Steel material and oil-well steel pipe

A steel material is provided which has excellent SSC resistance even in high-pressure H ...

QUENCH SYSTEM FOR PIPES

Spray quench systems for heat treated metal products

Ultra high strength alloy for severe oil and gas environments and method of preparation

High chromium martensitic heat-resistant steel with combined high creep rupture strength and oxidation resistance

Martensitic heat-resistant steel for boiler applications with a unique combination of enhanced creep strength and excellent oxidation resistance upon high temperature exposure in steam containing environments., having the following melt analysis (in wt.-%): C: 0.10 to 0.16%, Si: 0.20 to 0.60%, Mn: 0.30 to 0.80%, P ≤0.020%, S ≤0.010%, Al ≤0.020%, Cr: 10.5 to 12.00%, Mo: 0.10 to 0.60%, V: 0.15 to 0.30%, Ni: 0.10 to 0.40%, B: 0.008 to 0.015%, N :0.002 to 0.020%, Co: 1.50 to 3.00%, W: 1.50 to 2.50%, Nb: 0.02 to 0.07%, Ti: 0.001-0.020%. The balance of the steel consists of iron and unavoidable impurities. The steel is normalized for a period of about 10 to about 120 minutes in the temperature range between 1050 °C and 1170°C and cooled down in air or water to room temperature, and then tempered for at least one hour in the temperature range between 750°C and 820°C. It exhibits martensitic microstructure with average δ-ferrite content of less than 5 vol.-%.

Steel material, steel pipe for oil wells, and method for producing steel material

Provided are a steel material and a steel pipe for oil wells, which have excellent SSC resistance and high strength, namely a yield strength of 862 MPa or more but less than 965 MPa. A steel material according to the present invention has a chemical composition that contains, in mass%, 0.25-0.50% of C, 0.05-0.50% of Si, 0.05-1.00% of Mn, 0.025% or less of P, 0.0100% or less of S, 0.005-0.100% of Al, 0.30-1.50% of Cr, 0.25-1.50% of Mo, 0.002-0.050% of Ti, 0.0001-0.0050% of B, 0.002-0.010% of N and 0.0100% or less of O, with the balance made up of Fe and impurities. This steel material additionally contains 0.010-0.050 mass% of solid-solved C. This steel material has a yield strength of 862 MPa or more but less than 965 MPa, and a yield ratio of 90% or more.

Seamless steel pipe and method for producing same

A seamless steel pipe comprises a specific carbide that has an equivalent carbon content (Ceq) of 0.50 to 0.58%, contains Mo in an amount of 50 mass% or more, contains V, additionally contains one or two components selected from the group consisting of Ti and Nb, and has a size of 20 nm or more.

High-nitrogen stainless steel pipe with high strength, high ductility, and excellent corrosion and heat resistance and process for producing same

Provided is a novel high-nitrogen stainless-steel pipe which is not obtained with any conventional technique, the stainless-steel pipe having high strength, high ductility, and excellent corrosion and heat resistance and being obtained through size reduction of crystal grains and strengthening by slight plastic working besides formation of a gradient structure in which the concentration of solid-solution nitrogen continuously decreases gradually from the surface. Also provided are hollow materials of various shapes and sizes which are formed from the steel pipe and processes for producing the steel pipe and the hollow materials. An austenitic stainless-steel pipe is treated in a range of the temperatures not higher than the critical temperature for crystal grain enlargement of the steel pipe material to cause nitrogen (N) to be absorbed into the surface of the pipe and diffused into the solid phase, while minimizing the enlargement of crystal grains during the treatment. Thus, a gradient structure is formed, the structure including a part that is close to the surface part of the pipe and has been highly strengthened by the formation of a high-concentration solid solution of N and a part in which ductility gradually increases toward around the center of the cross-section of the pipe as the N concentration decreases. Thereafter, the pipe is subjected to size reduction of crystal grains by utilizing, for example, eutectoid transformation of the austenite phase, thereby greatly improving the elongation (ductility) of the steel pipe. Furthermore, the steel pipe is strengthened by slight plastic working to give a high-nitrogen austenitic stainless-steel pipe having high strength, high ductility, and excellent corrosion and heat resistance. A plurality of the thus-obtained high-nitrogen austenitic stainless steel pipes of the same quality are disposed one over another so as to result in dimensions, e.g., diameter and wall thickness, according to the use or strength level, ...

Method for inhibiting corrosion under insulation on the exterior of a structure

A method for inhibiting corrosion under insulation (CUI) on the exterior of a structure, e.g., pipelines, piping, vessels and tanks, is provided. The method involves providing a structure that is at least partially formed from a corrosion resistant carbon steel (CRCS) composition. The CRCS composition includes corrosion resistance alloying additions in the amount of 0.1 weight percent to 9 weight percent. At least one alloying addition has a low free energy of formation for its oxide and/or hydroxide, e.g., vanadium and/or titanium. A corrosion inhibited structure that includes a structure at least partially formed from a corrosion resistant carbon steel (CRCS) composition, and insulation positioned around at least a portion of the structure.

Method for generating a stress reduction in erected tube walls of a steam generator

In the case of a method for the heat treatment of erected, preferably large-area tube wall regions or tube wall segments, in particular of a diaphragm wall, of a steam generator, in particular of a power plant, in the installed state, it is sought to provide a solution which permits the use of steel types which are more problematic with regard to power plant operation with elevated steam parameters, in particular the steels T23 and T24, in the erection of steam generators. This is achieved in that the tube wall regions or tube wall segments for heat treatment are subjected, in the installed state in the steam generator, and in particular over a large area, to a stress-relief annealing process.

METHOD FOR QUENCHING STEEL PIPE AND METHOD FOR PRODUCING STEEL PIPE USING THE SAME

In quenching, where a heated steel pipe () is immersed in a water bath () in parallel with water surface for cooling a pipe outer surface, and cooling water is injected from an axial center nozzle () into one end of pipe for cooling a pipe inner surface, thereby rapidly cooling the entire pipe surface, reduction of strength difference along a length of the quenched pipe becomes possible by moving the nozzle () following the motion of the pipe axis (), and starting injecting the water from the nozzle () so as for the water to reach the other pipe end at the time of the immersion of the entire circumference of the pipe outer surface. An opening () preferably faces the nozzle () to remove the water, and the flow velocity is preferably set to 23 m/sec or more for better water flow inside the pipe (). 1. A method for quenching a steel pipe , in which a heated steel pipe is immersed in a water bath with an axis thereof being kept in parallel with water surface to primarily cool an outer surface of the steel pipe , and a water flow from one end of the steel pipe to the other end thereof is generated in an axial portion of the steel pipe by injecting cooling water from an axial center nozzle to primarily cool an inner surface of the steel pipe , so that an entire surface of the steel pipe is rapidly cooled , the method for quenching a steel pipe comprising:moving the axial center nozzle following the motion of the axis of the steel pipe, andwhen the injection of cooling water is started from the axial center nozzle while keeping immersing the steel pipe in the water bath, starting the injection of cooling water such that the cooling water injected into one end of the steel pipe at the start of the injection arrives at the other end just at the time that an entire circumference of the outer surface of the steel pipe is made to be immersed.2. The method for quenching a steel pipe according to claim 1 , wherein an opening is provided opposite to the axial center nozzle on a ...

INJECTOR NOZZLE QUENCHING PROCESS FOR PIPING SYSTEMS

A quenching process for quenching a flowing first fluid with a flowing second fluid may involve a first hollow pipe for containing the flowing first fluid and a second hollow pipe for containing the flowing second fluid; dividing the flowing second fluid into a first baffle flow along a first side of a longitudinal baffle and a second baffle flow along a second side of the longitudinal baffle within the second hollow pipe; providing a transverse baffle protruding from the longitudinal baffle for directing the first baffle flow from a first baffle flow outlet and the second baffle flow from a second baffle flow outlet in the second hollow pipe and into the flowing first fluid in the first hollow pipe; and configuring an area of the first baffle flow outlet area to be greater than or equal to an area of the second baffle flow outlet area. 1. A quenching process comprising:providing a first hollow pipe for containing a first fluid and a second hollow pipe for containing a second fluid;containing the second fluid as a single flow upstream of a longitudinal baffle within the second hollow pipe;dividing the second fluid into a first baffle flow along a first side of the longitudinal baffle and a second baffle flow along a second side of the longitudinal baffle within the second hollow pipe; anddirecting the first baffle flow from a first baffle flow outlet and the second baffle flow from a second baffle flow outlet in the second hollow pipe and into the first fluid in the first hollow pipe, the first baffle flow outlet having a first baffle flow outlet area and the second baffle flow outlet having a second baffle flow outlet area that together equal a total outlet area.2. The quenching process according to claim 1 , further comprising:defining hole in the wall of the first hollow pipe;providing the second hollow pipe through the hole in the wall of the first hollow pipe; andperpendicularly positioning the longitudinal baffle to a longitudinal axis of the first hollow pipe ...

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°.

PROCESSES FOR PRODUCING THICKER GAGE PRODUCTS OF NIOBIUM MICROALLOYED STEEL

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

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. ...

OVERHEATING-INSENSITIVE FINE GRAINED ALLOY STEEL FOR USE IN DOUBLE HIGH-FREQUENCY HEAT TREATMENT AND METHOD OF MANUFACTURING THE SAME

A fine-grained alloy steel includes iron (Fe) as a main component, and 0.40 to 0.55% by weight of carbon (C), 0.20 to 0.40% by weight of silicon (Si), 0.8 to 1.0% by weight of manganese (Mn), 0.8 to 1.2% by weight of chromium (Cr), 0.045% by weight of aluminum (Al), and inevitable impurities, based on a total weight of the alloy steel. 1. A fine-grained alloy steel comprising iron (Fe) as a main component , and 0.40 to 0.55% by weight of carbon (C) , 0.20 to 0.40% by weight of silicon (Si) , 0.8 to 1.0% by weight of manganese (Mn) , 0.8 to 1.2% by weight of chromium (Cr) , 0.045% by weight of aluminum (Al) , and inevitable impurities , based on a total weight of the fine-grained alloy steel.2. The fine-grained alloy steel according to claim 1 , further comprising molybdenum (Mo) claim 1 ,wherein Mo is present at a content of 0.20 to 0.45% by weight based on the total weight of the fine-grained alloy steel.3. The fine-grained alloy steel according to claim 1 , further comprising titanium (Ti) claim 1 ,wherein Ti is present at a content of 0.030% by weight based on the total weight of the fine-grained alloy steel.4. The fine-grained alloy steel according to claim 1 , further comprising niobium (Nb) claim 1 ,wherein Nb is present at a content of 0.025 to 0.05% by weight based on the total weight of the fine-grained alloy steel.5. The fine-grained alloy steel according to claim 1 , further comprising boron (B) claim 1 ,wherein B is present at a content of 0.0020 to 0.0040% by weight based on the total weight of the alloy steel.6. The fine-grained alloy steel according to claim 1 , further comprising Mo claim 1 , Ti claim 1 , Nb claim 1 , and boron (B) claim 1 ,wherein Mo is present at a content of 0.20 to 0.45% by weight, Ti is present at a content of 0.030% by weight, Nb is present at a content of 0.025 to 0.05% by weight, and B is present at a content of 0.0020 to 0.0040% by weight, based on the total weight of the fine-grained alloy steel.7. The fine-grained alloy ...

HEAT TREATMENT SYSTEM AND HEAT TREATMENT METHOD

The present invention addresses the issue of providing a heat treatment system and a heat treatment method whereby the inner circumference of a cylindrical workpiece can be reliably cooled regardless of the dimensions or shape of the workpiece and productivity can be improved, during quenching of the inner circumference of the cylindrical workpiece. The present invention has: rotating devices that rotate the cylindrical workpiece : holding members that hold the cylindrical workpiece at a prescribed position; a heating member that heats the cylindrical workpiece from the inner circumferential surface side; a cooling device that injects cooling fluid and cools the cylindrical workpiece from the outer circumferential surface side; and a injecting device provided at a position separated from the cooling device and which inject the cooling fluid. 1. A heat treatment system , characterized in that said system comprises:a rotating device which rotates a cylindrical workpiece;a holding member which holds the cylindrical workpiece at a predetermined position;a heating member which heats the cylindrical workpiece from an inner circumferential surface side;a cooling device which cools the cylindrical workpiece from an outer circumferential surface side by injecting a cooling liquid;an injecting device which is mounted at a position remote from the cooling device and injects the cooling liquid;a heating member holding member which hold the heating member fixedly in position;a cooling device holding member which hold the cooling device fixedly in position; anda base member to which the rotating device and the injecting device are attached and which moves relative to the heating member and the cooling device, whereinthe heating member has a function for heating the inner circumferential surface side of the cylindrical workpiece in a case that the base member moves and the heating member is positioned in a radial inner region of the cylindrical workpiece which has been held by the ...

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 ...

Lightweight door beam, composition thereof and method of manufacturing the same

A steel composition, a reinforcement part of a vehicle using the steel composition and a method of manufacturing the reinforcement part using the steel composition are provided. In particular, the steel composition includes increased content of carbon components and the steel composition is processed by rapid heating and immediate quenching.

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 ...

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.

Flowforming corrosion resistant alloy tubes

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

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 ...

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 ...

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 ...

Steel Material, Oil-Well Steel Pipe, and Method for Producing Steel Material

The steel material according to the present invention contains a chemical composition consisting of, in mass %, C: 0.25 to 0.50%, Si: 0.05 to 0.50%, Mn: 0.05 to 1.00%, P: 0.025% or less, S: 0.0100% or less, Al: 0.005 to 0.100%, Cr: 0.30 to 1.50%, Mo: 0.25 to 1.50%, Ti: 0.002 to 0.050%, B: 0.0001 to 0.0050%, N: 0.002 to 0.010% and O: 0.0100% or less, with the balance being Fe and impurities. The steel material also contains an amount of dissolved C within a range of 0.010 to 0.050 mass %. The steel material also contains an yield strength is in a range of 862 to less than 965 MPa, and an yield ratio is 90% or more. 1. A steel material comprising:a chemical composition consisting of, in mass %,C: 0.25 to 0.50%,Si: 0.05 to 0.50%,Mn: 0.05 to 1.00%,P: 0.025% or less,S: 0.0100% or less,Al: 0.005 to 0.100%,Cr: 0.30 to 1.50%,Mo: 0.25 to 1.50%,Ti: 0.002 to 0.050%,B: 0.0001 to 0.0050%,N: 0.002 to 0.010%,O: 0.0100% or less,V: 0 to 0.30%,Nb: 0 to 0.100%,Ca: 0 to 0.0100%,Mg: 0 to 0.0100%,Zr: 0 to 0.0100%,Co: 0 to 0.50%,W: 0 to 0.50%,Ni: 0 to 0.50%, andCu: 0 to 0.50%,with the balance being Fe and impurities,an amount of dissolved C within a range of 0.010 to 0.050 mass %,a yield strength within a range of 862 to less than 965 MPa, anda yield ratio of 90% or more.2. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from the group consisting of:V: 0.01 to 0.30%, andNb: 0.002 to 0.100%.3. The steel material according to claim 1 , wherein the chemical composition contains one or more types of element selected from the group consisting of:Ca: 0.0001 to 0.0100%,Mg: 0.0001 to 0.0100%, andZr: 0.0001 to 0.0100%.48-. (canceled)9. The steel material according to claim 2 , wherein the chemical composition contains one or more types of element selected from the group consisting of:Ca: 0.0001 to 0.0100%,Mg: 0.0001 to 0.0100%, andZr: 0.0001 to 0.0100%.10. The steel material according to claim 1 , wherein the chemical ...

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 Making Clad Metal Pipe

A method of producing a nickel alloy clad steel pipe including: providing a hollow cylinder of nickel alloy cladding material and a hollow cylinder of steel, placing the hollow cylinder of the nickel alloy cladding material concentrically inside the hollow cylinder of steel or the hollow cylinder of the steel concentrically inside the hollow cylinder of nickel alloy cladding material to form a composite billet, heating the composite billet to 1121-1260° C., and extruding the composite billet, wherein the nickel alloy cladding material comprises 6.0-12.0 wt. % molybdenum, 19.0-27.0 wt. % chromium, 1.0 wt. % maximum tungsten, 0.6 wt. % maximum aluminum, 0.6 wt. % maximum titanium, 0.001-0.05 wt. % carbon, 0.001-0.035 wt. % nitrogen, 0.001-0.3 wt. % silicon, 1.0 wt. % maximum niobium, 2.5 wt. % maximum iron, 0.5 wt. % maximum manganese, 0.015 wt. % maximum phosphorous, 0.015 wt. % maximum sulfur, 1.0 wt. % maximum cobalt, and the balance nickel and may have a solidus temperature greater than 1312° C. 1. A method of producing a nickel alloy clad steel pipe comprising:providing a hollow cylinder of nickel alloy cladding material and a hollow cylinder of steel;placing the hollow cylinder of the nickel alloy cladding material concentrically inside the hollow cylinder of steel to form a composite billet;heating the composite billet to an extrusion temperature of 1121-1260° C.; andextruding the heated composite billet,wherein the nickel alloy cladding material comprises 6.0 to 12.0 wt. % molybdenum, 19.0 to 27.0 wt. % chromium, 1.0 wt. % maximum tungsten, 0.6 wt. % maximum aluminum, 0.6 wt. % maximum titanium, 0.001 to 0.05 wt. % carbon, 0.001 to 0.035 wt. % nitrogen, 0.001 to 0.3 wt. % silicon, 1.0 wt. % maximum niobium, 2.5 wt. % maximum iron, 0.5 wt. % maximum manganese, 0.015 wt. % maximum phosphorous, 0.015 wt. % maximum sulfur, 1.0 wt. % maximum cobalt, and the balance nickel and incidental impurities.2. The method according to claim 1 , wherein the nickel alloy ...

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 ...

MARTENSITIC STAINLESS STEEL SEAMLESS PIPE FOR OIL COUNTRY TUBULAR GOODS, AND METHOD FOR MANUFACTURING SAME

The disclosure is intended to provide a martensitic stainless steel seamless pipe for oil country tubular goods having high strength and excellent sulfide stress corrosion cracking resistance and a method for manufacturing thereof. The martensitic stainless steel seamless pipe for oil country tubular goods has a composition that contains, in mass %, C: 0.0100% or more, Si: 0.5% or less, Mn: 0.25 to 0.50%, P: 0.030% or less, S: 0.005% or less, Ni: 4.6 to 8.0%, Cr: 10.0 to 14.0%, Mo: 1.0 to 2.7%, Al: 0.1% or less, V: 0.005 to 0.2%, N: 0.1% or less, Ti: 0.06 to 0.25%, Cu: 0.01 to 1.0%, and Co: 0.01 to 1.0%, in which C, Mn, Cr, Cu, Ni, Mo, W, Nb, N, and Ti satisfy predetermined relations, and the balance is Fe and incidental impurities. The martensitic stainless steel seamless pipe has a yield stress of 758 MPa or more. 1. A martensitic stainless steel seamless pipe for oil country tubular goods , the martensitic stainless steel seamless pipe having a yield stress of 758 MPa or more and a composition comprising , in mass % ,C: 0.0100% or more,Si: 0.5% or less,Mn: 0.25 to 0.50%,P: 0.030% or less,S: 0.005% or less,Ni: 4.6 to 8.0%,Cr: 10.0 to 14.0%,Mo: 1.0 to 2.7%,Al: 0.1% or less,V: 0.005 to 0.2%,N: 0.1% or less,Ti: 0.06 to 0.25%,Cu: 0.01 to 1.0%,Co: 0.01 to 1.0%, anda balance including Fe and incidental impurities, (i) all of the relations in formula (4) below, wherein value (1), value (2), and value (3) are obtained from formulae (1), (2), and (3), respectively, and', [{'br': None, '−109.37C+7.307Mn+6.399Cr+6.329Cu+11.343Ni−13.529Mo+1.276W+2.925Nb+196.775N−2.621Ti−120.307\u2003\u2003Formula (1)'}, {'br': None, '−0.0278Mn+0.0892Cr+0.00567Ni+0.153Mo−0.0219W−1.984N+0.208Ti−1.83\u2003\u2003Formula (2)'}, {'br': None, '−1.324C+0.0533Mn+0.0268Cr+0.0893Cu+0.00526Ni+0.0222Mo−0.0132W−0.473N−0.5Ti−0.514\u2003\u2003Formula (3)'}, {'br': None, '−35.0≤value of (1)≤45.0, −0.600≤value of (2)≤−0.250, and −0.400≤value of (3)≤0.010\u2003\u2003Formula (4)'}, {'br': None, 'Ti<6.0C\u2003\ ...

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.

Hardening Method of Annular Workpiece

A hardening method for an annular workpiece made of metal includes a heating process that heats the annular workpiece to a hardening temperature; an analyzing process that obtains a diameter of the annular workpiece heated to the hardening temperature, and divides the heated annular workpiece into at least a small diameter portion and a large diameter portion based on the obtained diameter; and a cooling process that injects cooling liquid under an injection condition toward the annular workpiece that has been divided into at least the large diameter portion and the small diameter portion in the analyzing process such that a dimensional difference between the large diameter portion and the small diameter portion decreases, the injection condition for the large diameter portion being different from the injection condition for the small diameter portion. 1. A hardening method for an annular workpiece made of metal , comprising:a heating process that heats the annular workpiece to a hardening temperature;an analyzing process that obtains a diameter of the annular workpiece heated to the hardening temperature, and divides the heated annular workpiece into at least a small diameter portion and a large diameter portion based on the obtained diameter; anda cooling process that injects cooling liquid under an injection condition toward the annular workpiece that has been divided into at least the large diameter portion and the small diameter portion in the analyzing process such that a dimensional difference between the large diameter portion and the small diameter portion decreases, the injection condition for the large diameter portion being different from the injection condition for the small diameter portion.2. The hardening method according to claim 1 , whereinthe annular workpiece is made a martensitic structure with no incompletely hardened structure, by the cooling process.3. The hardening method according to claim 1 , whereinin the cooling process, the injection ...

THICK-WALLED HIGH-STRENGTH SEAMLESS STEEL PIPE WITH EXCELLENT SOUR RESISTANCE FOR PIPE FOR PIPELINE, AND PROCESS FOR PRODUCING SAME

A heavy wall and high strength seamless steel pipe having high sour resistance is provided. In particular, a quenching and tempering treatment is conducted to adjust the yield strength to be higher than 450 MPa and adjust the Vickers hardness HV5 that can be measured at an outermost side or an innermost side of the pipe under a 5 kgf load (test load: 49 N) to be 250 HV5 or less. 1. A seamless steel pipe having a yield strength exceeding 450 MPa and prepared by performing a quenching and tempering treatment , wherein a Vickers hardness HV5 that can be measured at an outermost side or an innermost side of the pipe under a 5 kgf load (test load: 49 N) is 250 HV5 or less.2. The seamless steel pipe according to claim 1 , wherein a hardness distribution across the entire region of the seamless steel pipe in a wall thickness direction has an M-shape profile.3. The seamless steel pipe according to claim 1 , wherein a hardness distribution across the entire region of the seamless steel pipe in a wall thickness direction has a U-shape profile.4. The seamless steel pipe according to claim 2 , wherein the hardness distribution across the entire region of the seamless steel pipe in a wall thickness direction has the M-shape profile and a maximum hardness in terms of a Vickers hardness HV5 measured under a 5 kgf load (test load: 49 N) is 250 HV5 or less.6. The seamless steel pipe according to claim 5 , wherein the composition further contains claim 5 , in terms of mass % claim 5 , at least one selected from Cr: 0.5% or less claim 5 , Mo: 0.3% or less claim 5 , Ni: 0.3% or less claim 5 , Cu: 0.3% or less claim 5 , V: 0.05% or less claim 5 , and Nb: 0.05% or less.7. The seamless steel pipe according to claim 5 , wherein the composition further contains claim 5 , in terms of mass % claim 5 , Ca: 0.002% or less.10. The method for producing a seamless steel pipe according to claim 9 , wherein the rapid cooling includes claim 9 , instead of performing the water-cooling treatment in a ...

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 AND TOOL FOR HARDENING A HOLLOW PROFILE OF A STEEL WORKPIECE

Disclosed herein is a method and tool for hardening a hollow profile of a steel workpiece having an interior space. The method includes the steps of providing a workpiece having a hollow profile, heating the hollow profile, placing the hollow profile of the steel workpiece in a hardening tool, and cooling the hollow profile from the inside by way of a cooling core having an exterior shape that is complimentary to that of the structural shape of the interior space of the hollow profile. 1. A method of hardening a hollow profile of a steel workpiece , the method comprising:providing a steel workpiece having a hollow profile defining an interior space therein;heating the hollow profile of the steel workpiece;placing the hollow profile of the steel workpiece in a hardening tool; andcooling the hollow profile in the hardening tool by insertion of a cooling core into the interior space of the hollow profile, the cooling core having a shape complimentary to that of the interior space of the hollow profile.2. The method of claim 1 , further comprising directing a flow of a cooling medium through an interior of the cooling core claim 1 , so as to cool the cooling core.3. The method of claim 1 , further comprising cooling the cooling core by an external device.4. The method of claim 1 , wherein the cooling core is at least partially in contact with an inner surface of the hollow profile of the workpiece in the interior space.5. The method of claim 1 , wherein said step of placing the hollow profile of the steel workpiece in the hardening tool is performed after said step of heating the hollow profile.6. The method of claim 1 , further comprising:removing a surface layer from the hollow profile during said cooling step.7. The method of claim 6 , wherein said removing step includes applying dry ice to at least one of an outer surface of the hollow profile or the inner surface of the hollow profile in order to remove the surface layer.8. The method of claim 6 , wherein said ...

FORMING APPARATUS AND FORMING METHOD

A forming apparatus that forms a metal pipe includes: a heating unit which heats a metal pipe material; a gas supply unit which supplies gas into a heated metal pipe material, thereby expanding the metal pipe material; a die which forms the metal pipe by bringing the expanded metal pipe material into contact with the die; a cooling unit which cools the metal pipe after the forming by a cooling medium; and a control unit which controls an operation of the die, the gas supply unit, and the cooling unit, wherein the control unit makes cooling of the metal pipe by the cooling medium be performed, by controlling an operation of the die such that the die is opened and controlling the cooling unit such that the cooling unit brings the cooling medium into contact with the metal pipe, subsequently to completion of forming by the die. 1. A forming apparatus that forms a metal pipe , comprising:a heating unit which heats a metal pipe material;a gas supply unit which supplies gas into a heated metal pipe material, thereby expanding the metal pipe material;a die which forms the metal pipe by bringing the expanded metal pipe material into contact with the die;a cooling unit which cools the metal pipe after the forming by a cooling medium; anda control unit which controls an operation of the die, the gas supply unit, and the cooling unit,wherein the control unit makes cooling of the metal pipe by the cooling medium be performed, by controlling an operation of the die such that the die is opened and controlling the cooling unit such that the cooling unit brings the cooling medium into contact with the metal pipe, subsequently to completion of forming by the die.2. The forming apparatus according to claim 1 , wherein the control unitmakes cooling of the metal pipe by the die be performed, by controlling an operation of the die such that a state where the die and the metal pipe are brought into contact with each other is maintained for a predetermined time, after the completion of ...

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 ...

METHOD FOR MANUFACTURING SUPERIOR 13CR FRICTION-WELDED DRILLROD

The present invention provides a method for manufacturing a superior 13Cr friction-welded drillrod, the method comprising the following steps: manufacturing a superior 13Cr tube body; manufacturing a superior 13Cr internally threaded coupler and a superior 13Cr externally threaded coupler, respectively; connecting the superior 13Cr internally threaded coupler and the superior 13Cr externally threaded coupler respectively to the two ends of the superior 13Cr tube body by means of frictional butt welding; after heating seam areas to 950° C.-1000° C., cooling same to below 200° C. by ejecting compressed air onto the surfaces of the seam areas, and then cooling the seam areas to room temperature by spraying water; and tempering the seam areas by heating same to 640° C.-700° C. By the present method, a superior 13Cr friction-welded drillrod can be manufactured, which, in the case of the exploration of a gas filed containing a relatively high level of CO2, can be not only used as a drillrod in an earlier stage of nitrogen well-drilling operation, but also used as an oil tube in a later stage of well completion with oil tube. 1. A method for manufacturing a 13Cr friction-welded drillrod , the method comprising:a) manufacturing a 13Cr tube body having two opposing ends;b) manufacturing a 13Cr internally threaded coupler and a 13Cr externally threaded coupler, respectively;c) connecting the 13Cr internally threaded coupler and the 13Cr externally threaded coupler respectively to the two opposing ends of the 13Cr tube body;d) heating seam areas between the coupler and tube ends to 950° C.-1000° C;e) cooling the heated seam areas to below 200° C.;f) cooling the seam areas to room temperature; andg) tempering the seam areas by heating the seam areas to 640° C.-700° C.2. The method of claim 1 , wherein the 13Cr tube body claim 1 , 13Cr internally threaded coupler and 13Cr externally threaded coupler comprise 0.01%-0.05 wt % carbon (C) claim 1 , ≦0.5 wt % silicon (Si) claim 1 , 0 ...

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 ...

METHOD FOR QUENCHING STEEL PIPE, EQUIPMENT FOR QUENCHING STEEL PIPE, AND METHOD FOR MANUFACTURING STEEL PIPE

The invention is intended to provide a method for quenching a steel pipe, equipment for quenching a steel pipe, and a method of manufacturing a steel pipe that enable a steel pipe to be conveyed at high speed. The method for quenching a steel pipe includes the steps of: conveying a steel pipe onto a rotatable supporting member using a walking-arm type revolving conveyance apparatus; and rapidly cooling the steel pipe with first spray nozzles disposed above the pipe while the steel pipe is being rotated about a pipe axis of the steel pipe on the rotatable supporting member in a state where movements of the steel pipe in a direction parallel to and in a direction perpendicular to the pipe axis are stopped. 1. A method for quenching a steel pipe ,the method comprising the steps of:conveying a steel pipe onto a rotatable supporting member using a walking-arm type revolving conveyance apparatus; andrapidly cooling the steel pipe with first spray nozzles disposed above the pipe while the steel pipe is being rotated about a pipe axis of the steel pipe on the rotatable supporting member in a state where movements of the steel pipe in a direction parallel to and in a direction perpendicular to the pipe axis are stopped,the first spray nozzles being disposed along an axial direction of the steel pipe with an angle of 20 to 70° from the uppermost part of the pipe in a circumferential direction,the first spray nozzles being disposed except a swept range W of the walking-arm type revolving conveyance apparatus in a longitudinal direction of the steel pipe,the first spray nozzles including inclined spray nozzles that are disposed by being tilted toward the swept range W, and flat spray nozzles that are disposed adjacent to the inclined spray nozzles at equal intervals with a predetermined pitch D in the longitudinal direction of the steel pipe,the inclined spray nozzles being disposed by being offset by a distance S from the predetermined pitch D, and being tilted with an angle θ ...

HEAT TREATMENT APPARATUS, HEAT TREATMENT METHOD FOR STEEL WORKPIECE, AND HOT BENDING METHOD FOR STEEL WORKPIECE

A heat treatment apparatus of one aspect of the present disclosure includes: a feed device that feeds a heat treatment workpiece downstream in a feed direction along a heat treatment workpiece pass-line; a heating device that includes a heating coil disposed downstream of the feed device in the feed direction and encircling the pass-line; a cooling device that is disposed adjacent to the heating coil, downstream of the heating coil in the feed direction, and encircling the pass-line; and a gas supply device that is disposed upstream of the heating coil in the feed direction, directly connected to the heating coil and encircling the pass-line, and that includes a plurality of gas compartments configured by internally partitioning the gas supply device in the feed direction. 1. A heat treatment apparatus , comprising:a feed device that feeds a heat treatment workpiece downstream in a feed direction along a heat treatment workpiece pass-line;a heating device that includes a heating coil disposed downstream of the feed device in the feed direction and encircling the pass-line;a cooling device that is disposed adjacent to the heating coil, downstream of the heating coil in the feed direction, and encircling the pass-line; anda gas supply device that is disposed upstream of the heating coil in the feed direction, directly connected to the heating coil and encircling the pass-line, and that includes a plurality of gas compartments configured by internally partitioning the gas supply device in the feed direction.2. The heat treatment apparatus of claim 1 , wherein the heating coil includes two turns claim 1 , and a filler is disposed between neighboring portions of the heating coil in the feed direction such that there are no gaps between the neighboring portions.3. A heat treatment apparatus claim 1 , comprising:a feed device that feeds a heat treatment workpiece downstream in a feed direction along a heat treatment workpiece pass-line;a heating device that includes a two- ...

Steel material having excellent corrosion resistance in dew condensation environment containing sulfide and method for producing same

The present invention relates to a steel material having excellent corrosion resistance for use in an oil tanker, a crude oil tank, and the like and, particularly to a steel material having excellent corrosion resistance in a dew condensation environment containing a sulfide gas and a method for producing the same.

3-D PRINTED COOLING CHANNELS TO PRODUCE PHS PARTS WITH TAILORED PROPERTIES

A hot stamping die includes a body having a stamping surface, and cooling channels within the body. The cooling channels are positioned to transfer heat from region(s) of the surface to the channels. The hot stamping die also includes a heating element within the body, separate and apart from the channels. The heating element is positioned to heat region(s) of the body different from the region(s) of the surface at a rate greater than heat transfer from the channels to the region(s) of the surface. 1. A hot stamping die comprising:a body having a stamping surface;cooling channels within the body positioned to transfer heat from region(s) of the surface to the channels; anda heating element within the body, separate and apart from the channels, and positioned to heat region(s) of the body different from the region(s) of the surface at a rate greater than heat transfer from the channels to the region(s) of the surface.2. The hot stamping die of claim 1 , wherein a heat transfer rate from the heating element to the body region(s) corresponds to a cooling rate of less than about 27 K/s.3. The hot stamping die of claim 1 , wherein a heat transfer rate from the channels to the surface region(s) corresponds to a cooling rate of greater than about 27 K/s.4. The hot stamping die of claim 1 , wherein the heating element is a heating coil.5. The hot stamping die of claim 1 , wherein the heating element is a heating channel configured to receive a heating fluid.6. The hot stamping die of claim 1 , wherein the heating element is a cavity in the body below the body region(s) configured to reduce heat transfer from the body region(s) to the channels.7. The hot stamping die of claim 1 , wherein the heating element is separated from the channels by an insulation barrier within the body.8. The hot stamping die of claim 7 , wherein the insulation barrier is a cavity.9. A hot stamping die comprising:a body having a stamping surface;cooling channels within the body configured to remove ...

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 ...

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 ...

VEHICLE UNDERBODY PART MATERIAL, METHOD FOR MANUFACTURING VEHICLE UNDERBODY PART MATERIAL, AND METHOD FOR MANUFACTURING VEHICLE UNDERBODY PART

To provide a technique capable of preventing or suppressing fatigue failure of a vehicle underbody part material by 3DQ. A vehicle underbody part material relating to this disclosure includes: a quenched and bent steel pipe; and a plating film layer provided on a surface of the steel pipe and containing 30 mass % or more of Al and having an Al—Fe alloy existing in a surface thereof. 1. A vehicle underbody part material comprising:a quenched and bent steel pipe; anda plating film layer provided on a surface of the steel pipe and containing 30 mass % or more of Al and having an Al—Fe alloy existing in a surface thereof.2. The vehicle underbody part material according to claim 1 ,wherein a surface roughness of the plating film layer is 3.5 μm or less in arithmetic mean roughness Ra specified under JIS B0601: 2013.3. The vehicle underbody part material according to claim 1 ,wherein an outermost layer of the plating film layer is composed of (30 to 60) mass % Al—Zn—(0 to 2.5) mass % Si—(0 to 5) mass % Mg—(20 to 50) mass % Fe hot-dip plating.4. The vehicle underbody part material according to claim 1 ,wherein an outermost layer of the plating film layer is composed of Al—(0 to 15) mass % Si—(20 to 70) mass % Fe hot-dip plating.5. The vehicle underbody part material according to claim 1 ,{'sub': 0.4', '0.6', '2', '2', '5', '3, 'wherein the Al—Fe alloy is at least one of FeAl, FeAl, FeAl, FeAl, and FeAl.'}6. A method for manufacturing a vehicle underbody part material comprising:heating a part of a steel pipe comprising a plating film layer containing 30 mass % or more of Al in a surface thereof at an average temperature increasing rate of 100° C./sec or more from 100° C. to a maximum heating temperature in a range of 850 to 1300° C.;bending a part of the steel pipe having reached the maximum heating temperature; andcooling the part of the steel pipe at an average cooling rate of 1000° C./sec or more and to an ultimate temperature of 350° C. or lower within two seconds ...

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 ...

HOLLOW STABILIZER

A hollow stabilizer has a tubular shape and is provided with a torsion section that is provided to a vehicle and that extends in the vehicle width direction; an arm section that extends in the front-back direction of the vehicle; and bent sections that connect the torsion section and the arm section. The hardness of the outer surface of the bent inner sides of the bent sections of the hollow stabilizer is 70% or more with respect to the hardness of the outer surface of the arm section. 1. A pipe-shaped hollow stabilizer provided to a vehicle , comprising:a torsion section extending in a vehicle width direction;an arm section extending in a vehicle front-rear direction; anda bent section connecting the torsion section and the arm section, whereina hardness of an outer surface of an inner bend side of the bent section is at least 70% of a hardness of an outer surface of the arm section.2. A pipe-shaped hollow stabilizer provided to a vehicle , comprising:a torsion section extending in a vehicle width direction;an arm section extending in a vehicle front-rear direction; anda bent section connecting the torsion section and the arm section, whereina hardness increasing treatment is performed on the bent section locally or from an inner surface side of the bent section.3. The hollow stabilizer according to claim 1 , whereint/D is equal to or greater than 0.18 but less than 0.5 where t and D denote a plate thickness and an outer diameter of the hollow stabilizer, respectively, andquenching is performed with cooling by jetting a coolant onto the outer surface of the inner bend side of the bent section.413-. (canceled)14. The hollow stabilizer according to claim 1 , whereint/D is equal to or greater than 0.25 but less than 0.275 where t and D denote a plate thickness and an outer diameter of the hollow stabilizer, respectively, andquenching is performed with cooling by jetting a coolant into the hollow stabilizer.15. The hollow stabilizer according to claim 1 , whereint/D is ...

METHOD OF MAKING QUENCHED AND TEMPERED STEEL PIPE WITH HIGH FATIGUE LIFE

A method for producing a high fatigue life quenched/tempered steel pipe comprises a quenching treatment of keeping an unquenched starting steel pipe having a composition that comprises, % by mass, C: 0.1 to 0.4%, Si: 0.5 to 1.5%, Mn: 0.3 to 2%, P: at most 0.02%, S: at most 0.01%, Cr: 0.1 to 2%, Ti: 0.01 to 0.1%, Nb: 0.01 to 0.1%, Al: at most 0.1%, B: 0.0005 to 0.01%, and N: at most 0.01%, with a balance of Fe and inevitable impurities, at 900 to 1100° C. for 10 to 60 seconds and then rapidly cooling it. The cooled pipe is subjected to a tempering treatment of keeping the pipe at 280 to 380° C. for 10 to 60 minutes. 13-. (canceled)4. A method for producing a high fatigue life quenched/tempered steel pipe , comprising quenching treatment of keeping an unquenched starting steel pipe having a composition that comprises , % by mass , C: 0.1 to 0.4% , Si: 0.5 to 1.5% , Mn: 0.3 to 2% , P: at most 0.02% , S: at most 0.01% , Cr: 0.1 to 2% , Ti: 0.01 to 0.1% , Nb: 0.01 to 0.1% , Al: at most 0.1% , B: 0.0005 to 0.01% , and N: at most 0.01% , with a balance of Fe and inevitable impurities , at 900 to 1100° C. for 10 to 60 seconds and then rapidly cooling it , followed by tempering treatment of keeping it at 280 to 380° C. for 10 to 60 minutes.5. The method for producing a high fatigue life quenched/tempered steel pipe as claimed in claim 4 , wherein the starting steel pipe further contains at least one of Ni: at most 0.5% claim 4 , Ca: at most 0.02% claim 4 , Mo: at most 0.5% and V: at most 0.5%.6. The method for producing a high fatigue life quenched/tempered steel pipe as claimed in claim 4 , wherein the starting steel pipe is formed by welding a steel plate having a wall thickness t of from 1 to 7 mm into a pipe having an outer diameter D of from 10 to 45 mm and satisfying D/t≧4. 1. Field of the InventionThe present invention relates to a steel pipe obtained through quenching and tempering treatment and excellent in fatigue characteristics, especially to such a quenched/ ...

Deformation correcting device

A deformation correcting device to correct a deformation occurring in a ring shaped article, which has been heated, while the heated ring shaped article is cooled, includes a support table, on which the ring shaped article in a heated condition is placed; a pair of receiving rolls; a press roll provided in opposition to the pair of the receiving rolls with the ring shaped article intervening therebetween; a press roll drive mechanism for driving the press roll between an advanced position, at which the press roll is urged against the outer peripheral surface of the ring shaped article, and a retracted position, at which the press roll is separated away from the outer peripheral surface of the ring shaped article; and a press roll rotating mechanism for rotating the press roll then urged against the ring shaped article by the press roll drive mechanism.

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 ...

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 ...

HIGH STRENGTH STAINLESS STEEL SEAMLESS PIPE FOR OIL COUNTRY TUBULAR GOODS

A high strength stainless steel seamless pipe for oil country tubular goods which is excellent in hot workability, has a high strength, suppresses scattering in the strength, and has excellent carbon dioxide corrosion resistance. The steel pipe has a yield strength of 655 MPa or more, and a chemical composition comprising, by mass%, C: 0.005 to 0.05%, Si: 0.05 to 0.50%, Mn: 0.20 to 1.80%, P: 0.030% or less, S: 0.005% or less, Cr: 12.0 to 17.0%, Ni: 4.0 to 7.0%, Mo: 0.5 to 3.0%, Al: 0.005 to 0.10%, V: 0.005 to 0.20%, Co: 0.01 to 1.0%, N: 0.005 to 0.15%, and 0: 0.010% or less with the balance being Fe and inevitable impurities. Cr, Ni, Mo, Cu, and C satisfy a specified expression, and Cr, Mo, Si, C, Mn, Ni, Cu, and N satisfy another specified expression. 1. A high strength stainless steel seamless pipe for oil country tubular goods with a yield strength of 655 MPa or more , the stainless steel seamless pipe having a chemical composition comprising , by mass %:C: 0.005 to 0.05%;Si: 0.05 to 0.50%;Mn: 0.20 to 1.80%;P: 0.030% or less.S: 0.005% or less;Cr: 12.0 to 17.0%;Ni: 4.0 to 7.0%;Mo: 0.5 to 3.0%;Al: 0.005 to 0.10%;V: 0.005 to 0.20%;Co: 0.01 to 1.0%;N: 0.005 to 0.15%;O: 0.010% or less; andthe balance being Fe and inevitable impurities, [{'br': None, 'Cr+0.65Ni+0.6Mo+0.55Cu−20C≥15.0\u2003\u2003(1)'}, {'br': None, 'Cr+Mo+0.3Si43.5C−0.4Mn−Ni−0.3Cu−9N≤11\u2003\u2003(2)'}], 'wherein the following expressions (1) and (2) are satisfiedwhere Cr, Ni, Mo, Cu, C, Si, Mn, and N are content, by mass %, of each respective element, and a content of any non-contained element is zero.2. The high strength stainless steel seamless pipe for oil country tubular goods according to claim 1 , further comprising claim 1 , by mass % claim 1 , at least one selected from the group consisting of Cu: 0.05 to 3.0% claim 1 , and W: 0.1 to 3.0%.3. The high strength stainless steel seamless pipe for oil country tubular goods according to claim 1 , further comprising claim 1 , by mass % claim 1 , at ...

HIGH STRENGTH STAINLESS STEEL SEAMLESS PIPE WITH EXCELLENT CORROSION RESISTANCE FOR OIL WELL AND METHOD OF MANUFACTURING THE SAME

A pipe having chemical composition contains, by mass %, C: 0.05% or less, Si: 0.5% or less, Mn: 0.15% or more and 1.0% or less, Cr: 13.5% or more and 15.4% or less, Ni: 3.5% or more and 6.0% or less, Mo: 1.5% or more and 5.0% or less, Cu: 3.5% or less, W: 2.5% or less, and N: 0.15% or less so that the relationship −5.9×(7.82+27C−0.91 Si+0.21Mn−0.9Cr+Ni−1.1Mo−0.55W+0.2Cu+11N)≧13.0 is satisfied. 112.-. (canceled)13. A high strength stainless steel seamless pipe with excellent corrosion resistance for an oil well , the pipe having a chemical composition containing , by mass % ,C: 0.05% or less, Si: 0.5% or less,Mn: 0.15% or more and 1.0% or less, P: 0.030% or less,S: 0.005% or less, Cr: 13.5% or more and 15.4% or less,Ni: 3.5% or more and 6.0% or less,Mo: 1.5% or more and 5.0% or less,Cu: 3.5% or less, W: 2.5% or less,N: 0.15% or less, {'br': None, '−5.9×(7.82+27C−0.91Si+0.21Mn−0.9Cr+Ni−1.1Mo−0.55W+0.2Cu+11N)≧13.0\u2003\u2003(1),'}, 'and the balance being Fe and inevitable impurities so that formula (1) below is satisfied by C, Si, Mn, Cr, Ni, Mo, W, Cu, and N: formula (1) is'}where C, Si, Mn, Cr, Ni, Mo, W, Cu, and N respectively denote the contents (mass %) of corresponding chemical elements.14. The high strength stainless steel seamless pipe according to claim 13 , wherein the pipe has a chemical composition further containing claim 13 , by mass % claim 13 , V: 0.02% or more and 0.12% or less.15. The high strength stainless steel seamless pipe according to claim 13 , wherein the pipe has a chemical composition further containing claim 13 , by mass % claim 13 , Al: 0.10% or less.16. The high strength stainless steel seamless pipe according to claim 13 , wherein the pipe has a chemical composition further containing claim 13 , by mass % claim 13 , one or more selected from among Nb: 0.02% or more and 0.50% or less claim 13 , Ti: 0.02% or more and 0.16% or less claim 13 , Zr: 0.50% or less claim 13 , and B: 0.0030% or less.17. The high strength stainless steel seamless ...

Thick-walled high-strength sour-resistant line pipe and method for producing same

A line pipe and a production method therefor are provided. The microstructure in the pipe thickness direction contains 90% or more bainite in a region that extends from a position 2 mm from an inner surface to a position 2 mm from an outer surface. In a hardness distribution in the pipe thickness direction, the hardness in a region other than a center segregation area is 220 Hv10 or less and the hardness in the center segregation area is 250 Hv0.05 or less. The major axes of pores, inclusions, and inclusion clusters that are present in a portion that extends from a position 1 mm from the inner surface to a 3/16 position of the tube thickness and in a portion that extends from a position 1 mm from the outer surface to a 13/16 position of the tube thickness in the tube thickness direction are 1.5 mm or less. A continuous casting slab having the above-described composition is hot-rolled under particular conditions and then subjected to accelerated cooling.

HEAVY WALL ELECTRIC RESISTANCE WELDED STEEL PIPE FOR LINE PIPE AND METHOD FOR MANUFACTURING THE SAME (AS AMENDED)

By using, as a raw material, a thick hot-rolled steel sheet having a chemical composition containing, by mass %, C: 0.02% or more and 0.10% or less, Si: 0.05% or more and 0.30% or less, Mn: 0.80% or more and 2.00% or less, and Nb: 0.010% or more and 0.100% or less and satisfying the condition that a carbon equivalent Ceq is 0.25% or more and 0.50% or less, a microstructure including a bainitic ferrite phase and/or a bainite phase, a high strength of 52 ksi or more in terms of yield strength and a high toughness of −45° C. or lower in terms of fracture transition temperature vTrs, and satisfying the condition that the ratio of the average crystal grain size of the coarsest-grain portion to the average crystal grain size of the finest-grain portion is 2.0 or less in every portion in the wall thickness direction is obtained 1. A heavy wall electric resistance welded steel pipe for a line pipe , the steel pipe being a heavy wall electric resistance welded steel pipe which is formed from a thick hot-rolled steel sheet as a raw material and which has a base metal zone and an electric resistance weld zone ,wherein the base metal zone has a chemical composition containing, by mass %, C: 0.02% or more and 0.10% or less, Si: 0.05% or more and 0.30% or less, Mn: 0.80% or more and 2.00% or less, and Nb: 0.010% or more and 0.100% or less and satisfying the condition that a carbon equivalent Ceq defined by equation (1) below is 0.25% or more and 0.50% or less, and a microstructure including a bainitic ferrite phase and/or a bainite phase,wherein the base metal zone has a high strength of 360 MPa or more in terms of yield strength and a high toughness of −45° C. or lower in terms of fracture transition temperature vTrs in a Charpy impact test,wherein the electric resistance weld zone has a microstructure including a bainitic ferrite phase and/or a bainite phase and satisfying the condition that the ratio of the average crystal grain size of a portion in the wall thickness ...

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: 0.25 to 0.50%, 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 0.050 mass %. The tensile yield strength in the axial direction and the circumferential direction is 862 to 965 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. 1. A steel pipe comprising:a chemical composition consisting of, in mass %,C: 0.25 to 0.50%,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%,O: 0.0030% or less,V: 0 to 0.300%,Nb: 0 to 0.100%,B: 0 to 0.0030%,Ca: 0 to 0.0100%,Mg: 0 to 0.0100%,Zr: 0 to 0.0100%,Co: 0 to 1.00%,W: 0 to 1.00%,Ni: 0 to 0.50%,Cu: 0 to 0.50%, andwith the balance being Fe and impurities,an amount of dissolved C within a range of 0.010 to 0.050 mass %,whereina tensile yield strength in an axial direction of the steel pipe is 862 to 965 MPa and a yield ratio in the axial direction of the steel pipe is 90% or more,a tensile yield strength in a circumferential direction of the steel pipe is 862 to 965 MPa, andthe tensile yield strength in the circumferential direction of the steel pipe is 30 to 80 MPa higher than a compressive yield strength in the circumferential direction of the steel pipe.2. The steel pipe according to claim 1 , wherein the chemical composition contains one or more types of element selected from the group consisting of:V: 0.010 to 0.300%, andNb: 0.002 to 0.100%.3. The steel pipe according to claim ...

LOW ALLOY OIL WELL STEEL PIPE AND METHOD FOR MANUFACTURING SAME

Low-alloy oil-well steel pipe includes a composition consisting, in mass %, of C: 0.40 to 0.65%, Si: 0.05 to 0.50%, Mn: 0.10 to 1.00%, P: 0.020% or less, S: 0.0020% or less, Cu: 0.15% or less, Cr: 0.40 to 1.50%, Mo: 0.50 to 2.50%, V: 0.05 to 0.25%, Ti: 0 to less than 0.01%, Nb: 0.01 to 0.2%, sol.Al: 0.010 to 0.100%, N: 0.006% or less, B: 0 to 0.0015%, and Ca: 0 to 0.003%, the balance being Fe and impurities. The structure has tempered martensite and 0 to less than 2% volume ratio of retained austenite. A grain size number of prior-austenite grain in the structure is 9.0 or more. An equivalent circular diameter of a sub-structure surrounded by a boundary having a crystal orientation difference of 15° or more from a packet boundary, a block boundary and a lath boundary is 3 μm or less for the tempered martensite. 1. A low-alloy oil-well steel pipe characterized by comprising:a chemical composition consisting, in mass %, ofC: 0.40 to 0.65%,Si: 0.05 to 0.50%,Mn: 0.10 to 1.00%,P: 0.020% or less,S: 0.0020% or less,Cu: 0.15% or less,Cr: 0.40 to 1.50%,Mo: 0.50 to 2.50%,V: 0.05 to 0.25%,Ti: 0 to less than 0.01%,Nb: 0.01 to 0.2%,sol.Al: 0.010 to 0.100%,N: 0.006% or less,B: 0 to 0.0015%, andCa: 0 to 0.003%, a structure consisting of tempered martensite and 0 to less than 2% in volume ratio of retained austenite,', 'wherein the steel pipe has yield strength of 965 MPa or more;', 'wherein a grain size number of a prior-austenite grain in the structure is 9.0 or more; and', 'wherein in the tempered martensite, a equivalent circular diameter of a sub-structure surrounded by a boundary having a crystal orientation difference of 15° or more from among a packet boundary, a block boundary and a lath boundary is 3 μM or less., 'the balance being Fe and impurities; and'}2. A method for manufacturing a low-alloy oil-well steel pipe , characterized by comprising:{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'a hot working step of hot-working a starting material having the chemical ...

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

There is provided a seamless steel pipe for line pipe, wherein a chemical composition consists, by mass percent, of C: 0.03-0.10%, Si: ≦0.50%, Mn: 1.0-2.0%, P: ≦0.050%, S: ≦0.005%, Cr: 0.05-1.0%, Mo: 0.01-0.30%, Al: 0.001-0.10%, N: ≦0.01%, Ni: 0.04-2.0%, Ca: 0.0005-0.0050%, Cu: 0-2.0%, Ti: 0-0.05%, Nb: 0-0.05%, V: 0-0.10%, the balance: Fe and impurities, and satisfies the conditions of Cu+Ni: ≧0.10%, and Mo+V: ≦0.30%, wherein 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 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 longer. 1. A seamless steel pipe for line pipe , wherein a chemical composition consists , by mass percent , ofC: 0.03 to 0.10%,Si: 0.50% or less,Mn: 1.0 to 2.0%,P: 0.050% or less,S: 0.005% or less,Cr: 0.05 to 1.0%,Mo: 0.01 to 0.30%,Al: 0.001 to 0.10%,N: 0.01% or less,Ni: 0.04 to 2.0%,Ca: 0.0005 to 0.0050%,Cu: 0 to 2.0%,Ti: 0 to 0.05%,Nb: 0 to 0.05%,V: 0 to 0.10%,the balance: Fe and impurities, andthe chemical composition satisfies the conditions ofCu+Ni: 0.10% or more, andMo+V: 0.30% or less, whereinin 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 longer.2. The seamless steel pipe for line pipe according to claim 1 , whereinthe chemical composition contains, by mass percent,one or more elements selected fromCu: 0.01 to 2.0%,Ti: 0.003 to 0.05%,Nb: 0.01 to 0.05%, andV: 0.02 to 0.10%.3. The seamless steel pipe for line pipe according to claim 1 , whereinthe chemical composition consists, by mass percent, ofC: 0.03 to 0.10%,Si: 0.30% or less,Mn: 1.00 to 1.80%,P: 0.020% or less ...

Tube product, hollow carrier of perforating gun and method of manufacturing the tube product

The present invention relates to a tube product, namely a perforating gun hollow carrier, consisting of a steel alloy with martensitic matrix, characterized in that it has a yield strength Rp0,2 of at least 900 MPa, and that the steel alloy besides iron and impurities caused by melting has the following alloying elements: 1. Tube product , namely a perforating gun hollow carrier , consisting of a steel alloy with martensitic matrix , characterized in that it has a yield strength Rp0 ,2 of at least 900 MPa , and that the steel alloy besides iron and impurities caused by melting has the following alloying elements:C 0.15-0.6%Si 1.4-2.6%Cr 2.0-4.0%Mn 0.15-2.0%Mo 0.2-0.6%N<0015% andat least one of the alloying elements Nb, V and Ti in sum of ≥0.01% andthe tube product has been subjected to a quenching and partitioning heat treatment.2. Tube product according to claim 1 , characterized in that the silicon content is in the range from 1.7 to 2.4% and preferably in the range from 1.8 to 2.2.3. Tube product according to claim 1 , characterized in that the chromium content is in the range from 2.5 to 3.5% and preferably in the range from 2.7 to 3.2.4. Tube product according to claim 1 , characterized in that the manganese content is less than 1.5 claim 1 , in particular less than 0.7%.5. (canceled)6. Tube product according to claim 1 , characterized in that at least one of the following alloying elements is present in the indicated amounts in the steel alloyNb 0.001-0.1%, preferably 0.015-0.05%V 0.025-0.5%Ti 0.015 to 0.1%Al 0.01-0.1%, preferably 0.015-0.06.7. Tube product according to claim 1 , characterized in that the steel alloy has nickel in an amount of maximum 3%.8. Tube product according to claim 1 , characterized in that the steel alloy has boron in an amount in the range of 0.001-0.004%.9. Tube product according to claim 1 , characterized in that the tube product has a microstructure of martensite and austenite claim 1 , wherein the portion of austenite is within ...

LOW-CARBON CHROMIUM STEEL HAVING REDUCED VANADIUM AND HIGH CORROSION RESISTANCE, AND METHODS OF MANUFACTURING

Embodiments of the present disclosure are direct to a low-carbon chromium steel, and methods for manufacturing said steel, having a low vanadium concentration. In some embodiments, the steel can have high corrosion resistance while retaining adequate strength and toughness. The steel can be manufactured through an austenitization process, followed by quenching at a controlled cooling rate, and tempering to form about 5 to 10% bainite, while limiting formation of chromium rich carbides.

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

Provided is a high-strength seamless stainless steel pipe for oil country tubular goods which possesses a high strength, excellent low-temperature toughness and excellent corrosion resistance even when the steel pipe has a large wall thickness. The high-strength seamless stainless steel pipe has the composition which contains, by mass %, C: 0.05% or less, Si: 1.0% or less, Mn: 0.1 to 0.5%, P: 0.05% or less, S: less than 0.005%, Cr: more than 15.0% to 19.0% or less, Mo: more than 2.0% to 3.0% or less, Cu: 0.3 to 3.5%, Ni: 3.0% or more and less than 5.0%, W: 0.1 to 3.0%, Nb: 0.07 to 0.5%, V: 0.01 to 0.5%, Al: 0.001 to 0.1%, N: 0.010 to 0.100%, O: 0.01% or less, and Fe and unavoidable impurities as a balance. Nb, Ta, C, N and Cu satisfy a specified formula. The steel pipe has a microstructure which is formed of 45% or more of a tempered martensite phase, 20 to 40% of a ferrite phase, and more than 10% and 25% or less of a residual austenite phase in terms of volume ratio. 1. A high-strength seamless stainless steel pipe for oil country tubular goods having a composition comprising:C: 0.05% or less, by mass %;Si: 1.0% or less, by mass %;Mn: 0.1 to 0.5%, by mass %;P: 0.05% or less, by mass %;S: less than 0.005%, by mass %;Cr: more than 15.0% to 19.0% or less, by mass %;Mo: more than 2.0% to 3.0% or less, by mass %;Cu: 0.3 to 3.5%, by mass %;Ni: 3.0% or more and less than 5.0%, by mass %;W: 0.1 to 3.0%, by mass %;Nb: 0.07 to 0.5%, by mass %;V: 0.01 to 0.5%, by mass %;Al: 0.001 to 0.1%, by mass %;N: 0.010 to 0.100%, by mass %;O: 0.01% or less, by mass %; andFe and unavoidable impurities, [ [{'br': None, 'sup': '−2.2', '5.1×{(Nb+0.5Ta)−10/(C+1.2N)}+Cu≥1.0\u2003\u2003(1),'}, 'where, Nb, Ta, C, N and Cu: contents (mass %) of respective elements are expressed as zero when not contained,, 'Nb, Ta, C, N and Cu satisfy a following formula (1), 'the steel pipe has a microstructure that is formed of 45% or more of a tempered martensite phase, 20 to 40% of a ferrite phase, and more ...

Steel pipe for fuel injection pipe and method for producing the same

A steel pipe for fuel injection pipe has a tensile strength of 500 to 900 MPa and a yield ratio of 0.50 to 0.85, and has a critical internal pressure (IP) satisfying [IP≥0.41×TS×α] (α=[(D/d) 2 −1]/[0.776×(D/d) 2 ], where TS: tensile strength (MPa) of the steel pipe, D: steel pipe outer diameter (mm), and d: steel pipe inner diameter (mm)), wherein a circumferential-direction residual stress on an inner surface of the pipe is −20 MPa or lower after the steel pipe is split in half in a pipe axis direction.

Method for Producing a Wear-Resistant Steel Pipe, Wear-Resistant Steel Pipe, and Use of Such a Steel Pipe

A process for the industrial production of wear-resistant steel pipes having an optimized life. The process includes providing a wear-resistant, hardenable steel sheet in an unhardened or tempered state, shaping the steel sheet into a tubular preform in which two longitudinal edges of the steel sheet are positioned opposite one another with a welding gap extending between the two edges, welding the longitudinal edges by forming a welded seam which closes the welding gap, thereby forming a steel pipe, and heat treating the steel pipe. The heat treatment of the steel pipe includes heating the steel pipe at an average heating rate of 5-400 K/s to a hold temperature which is ≥ the Ac3 temperature of the steel and ≥1100° C., holding the steel pipe at the hold temperature for 1-120 s, and cooling the steel pipe at an average cooling rate of 10-600 K/s to room temperature. 115.-. (canceled)16. A steel pipe having a diameter of at least 200 mm , a wall thickness of at least 15 mm and having a welded seam which extends linearly in the longitudinal direction of the steel pipe or runs helically around the longitudinal axis of the steel pipe , wherein the steel pipe is formed from a steel sheet comprising (in % by weight):C: 0.2-0.4%,Si: 0.6-0.9%,Mn: 1.0-2.0%optionally, one element or a plurality of elements selected from the group consisting of Cr, Mo, Ti, Ni, B, whereCr: 1.0-2.0%,Ti: up to 0.04%,Mo: 0.3-0.7%,Ni: up to 2.0%, andB: up to 0.004%,and iron and unavoidable impurities as the remainderandthe difference between a hardness of a heat affected zone (HAZ) adjoining the welded seam of the steel pipe and a hardness of the steel sheet outside of the heat affected zone is not more than 30 HV10.17. The steel pipe according to claim 16 , wherein the wall thickness is at least 40 mm.18. A process for producing a steel pipe according to claim 16 , comprising the following working steps:a) providing an at least 15 mm thick steel sheet which comprises a wear-resistant, hardenable ...

MARTENSITIC STAINLESS STEEL SEAMLESS PIPE FOR OIL COUNTRY TUBULAR GOODS, AND METHOD FOR MANUFACTURING SAME

A martensitic stainless steel seamless pipe for oil country tubular goods having a yield stress of 758 MPa or more, and excellent sulfide stress corrosion cracking resistance, and a method for manufacturing the same. The martensitic stainless steel seamless pipe has a composition that contains, by mass %, C: 0.010% or more, Si: 0.5% or less, Mn: 0.05 to 0.50%, P: 0.030% or less, S: 0.005% or less, Ni: 4.6 to 8.0%, Cr: 10.0 to 14.0%, Mo: 1.0 to 2.7%, Al: 0.1% or less, V: 0.005 to 0.2%, N: 0.1% or less, Ti: 0.255 to 0.500%, Cu: 0.01 to 1.0%, Co: 0.01 to 1.0%, and the balance being Fe and incidental impurities. C, Mn, Cr, Cu, Ni, Mo, W, Nb, N, and Ti satisfy a predetermined relationship. 1. A martensitic stainless steel seamless pipe for oil country tubular goods having a chemical composition comprising , by mass %:C: 0.010% or more;Si: 0.5% or less;Mn: 0.05 to 0.50%;P: 0.030% or less;S: 0.005% or less;Ni: 4.6 to 8.0%;Cr: 10.0 to 14.0%;Mo: 1.0 to 2.7%;Al: 0.1% or less;V: 0.005 to 0.2%;N: 0.1% or less;Ti: 0.255 to 0.500%;Cu: 0.01 to 1.0%;Co: 0.01 to 1.0%; andthe balance being Fe and incidental impurities, {'br': None, '−35≤−109.37C+7.307Mn+6.399Cr+6.329Cu+11.343Ni−13.529Mo+1.276W+2.925Nb+196.775N−2.621Ti−120.307≤45\u2003\u2003(1)'}, 'wherein the chemical composition satisfies the following formula (1)where C, Mn, Cr, Cu, Ni, Mo, W, Nb, N, and Ti represent the content of each element by mass %, and the content is 0% for elements that are not contained, andthe martensitic stainless steel seamless pipe has a yield stress of 758 MPa or more.2. The martensitic stainless steel seamless pipe for oil country tubular goods according to claim 1 , wherein the chemical composition further comprises claim 1 , by mass % claim 1 , at least one selected from the group consisting of Nb: 0.1% or less claim 1 , and W: 1.0% or less.3. The martensitic stainless steel seamless pipe for oil country tubular goods according to claim 1 , wherein the chemical composition further comprises claim 1 ...

Seamless Steel Pipe and Method for Producing Same

A seamless steel pipe is provided that has a chemical composition which consists of, by mass %, C: 0.10 to 0.20%, Si: 0.05 to 1.0%, Mn: 0.05 to 1.2%, P≤0.025%, S≤0.005%, Cu≤0.20%, N≤0.007%, Ni: 0.20 to 0.50%, Cr: 0.30% or more and less than 0.50%, Mo: 0.30 to 0.50%, Nb: 0.01 to 0.05%, Al: 0.001 to 0.10%, B: 0.0005 to 0.0020%, Ti: 0.003 to 0.050%, V: 0.01 to 0.20%, a total of any one or more elements among Ca, Mg and REM: 0 to 0.025%, and the balance: Fe and impurities, and for which Pcm (=C+(Si/30)+(Mn/20)+(Cu/20)+(Ni/60)+(Cr/20)+(Mo/15)+(V/10)+5B)≤0.30. The steel micro-structure includes, in area %, tempered martensite ≥90%. The tensile strength is 980 MPa or more, and a Charpy impact value at −40° C. using a 2 mm V-notch test specimen is 75 J/cmor more. 1. A seamless steel pipe having a chemical composition consisting of , by mass % ,C: 0.10 to 0.20%,Si: 0.05 to 1.0%,Mn: 0.05 to 1.2%,P: 0.025% or less,S: 0.005% or less,Cu: 0.20% or less,N: 0.007% or less,Ni: 0.20 to 0.50%,Cr: 0.30% or more and less than 0.50%,Mo: 0.30 to 0.50%,Nb: 0.01 to 0.05%,Al: 0.001 to 0.10%,B: 0.0005 to 0.0020%,Ti: 0.003 to 0.050%,V: 0.01 to 0.20%,a total of any one or more elements among Ca, Mg and REM: 0 to 0.025%, and the balance: Fe and impurities;wherein:a value of Pcm that is represented by Formula [A] below is 0.30 or less,a steel micro-structure comprises, in area %, tempered martensite: 90% or more,a tensile strength is 980 MPa or more, and{'sup': '2', 'claim-text': {'br': None, 'Pcm=C+(Si/30)+(Mn/20)+(Cu/20)+(Ni/60)+(Cr/20)+(Mo/15)+(V/10)+5B\u2003\u2003[A]'}, 'a Charpy impact value at −40° C. using a 2 mm V-notch test specimen is 75 J/cmor more.'}where, each symbol of an element in Formula [A] represents a content (mass %) of a corresponding element in the steel, with a value of a symbol being zero if the corresponding element is not contained.2. A method for producing a seamless steel pipe according to , the method comprising performing processes [i] to [iv] hereunder in sequence ...

RESISTANCE WELDING METHOD FOR SUCKER ROD

Embodiments of the present disclosure generally relate to apparatus and methods for connecting continuous sucker rods. Ends of two work pieces may be prepared by reducing cross sections of the ends. The two work pieces may be welded together by establishing a planar contact at the prepared ends and applying a current across the two work pieces while moving the work pieces relative to each other. 1. A welding station , comprising:a first clamp die adapted to secure a first work piece;a second clamp die adapted to secure a second work piece;an actuator coupled to move the first clamp die and second clamp die relative to each other; anda controller coupled to the actuator.2. The weld station of claim 1 , further comprising:a power supply coupled to the first clamp die and the second clamp die, wherein the controller is connected to the power supply.3. The weld station of claim 1 , wherein the first clamp die is stationary claim 1 , the second clamp die is movable relative to the first clamp die claim 1 , and the actuator is coupled to the second clamp die.4. The weld station of claim 3 , wherein the actuator comprises a hydraulic cylinder.5. The weld station of claim 3 , further comprising a position sensor adapted to measure position of the second clamp.6. The weld station of claim 3 , further comprising a force sensor.7. The weld station of claim 1 , wherein the controller comprises a storage unit having ranges of parameters stored therein.8. The weld station of claim 2 , wherein the power supply comprises a plurality of batteries.9. The weld station of claim 2 , wherein the current is applied across the first work piece and the second work piece.10. A method for welding continuous sucker rods claim 2 , comprising:preparing ends of a first work piece and a second work piece by reducing cross sections of the ends; andwelding the first work piece and the second work piece at the prepared ends.11. The method of claim 10 , wherein welding the first work piece and the ...

CORROSION RESISTANT STEEL, METHOD FOR PRODUCING SAID STEEL AND ITS USE THEREOF

The invention deals with a corrosion resistant steel of at least 758 MPa comprising in weight %: 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, 3.2×C×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, the balance of the chemical composition of said corrosion resistant steel being constituted by Fe and inevitable impurities. The invention deals also with the manufacturing method of such steel to obtain a quenched and tempered semi finished product. 1. A steel , having a yield strength of at least 758 MPa , the steel comprising , in weight %: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;3.2×C≤Nb≤0.1;W≤1.5;0.5≤Co≤1.5;0.02≤N≤0.05;Ti≤0.05;P≤0.03;S≤0.0035;Al≤0.05; andiron.2. The steel according to claim 1 , wherein the steel comprises claim 1 , in weight %: 15.5≤Cr≤16.5.3. The steel according to claim 1 , wherein the steel comprises claim 1 , in weight %: 0.8≤Cu≤1.2.4. The steel according to claim 1 , having a microstructure comprising between 30% and 50% of ferrite.5. The steel according to claim 1 , having a microstructure comprising between 5% and 15% of austenite.6. The steel according to claim 1 , having a microstructure comprising between 35% and 65% of martensite.7. The steel according to claim 1 , having a microstructure with less than 0.5% intermetallics in volume fraction.8. The steel according to claim 1 , having a microstructure with no intermetallics.9. The steel according to claim 1 , having a yield strength of at least 862 MPa (125 ksi).10. The steel according to claim 1 , having a fracture toughness resistance at −10° C. of at least 68 J.11. A manufacturing method of a steel tube claim 1 , the method comprising:{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'hot forming a steel composition according to at a temperature comprised between 1150° C. and 1260° C. by forging, rolling, and extruding to obtain a tube;'}heating the tube up to a temperature ...

MECHANICAL COMPONENT

There is provided a high-strength steel mechanical component. A mechanical component is a mechanical component composed of a steel having a carbon content of more than or equal to 0.2 mass % and less than or equal to 0.8 mass %, and includes a quench-hardened layer formed in a surface layer of the mechanical component. In the quench-hardened layer, a grain size number of prior austenite crystal grains is No. 11 or higher. Moreover, the quench-hardened layer may have a Vickers hardness of more than or equal to 500 HV. In this case, prior austenite crystal grains in the quench-hardened layer become fine, thereby providing the mechanical component with high strength. 1. A mechanical component composed of a steel having a carbon content of more than or equal to 0.2 mass % and less than or equal to 0.8 mass % , the mechanical component comprising a quench-hardened layer formed in a surface layer of the mechanical component ,in the quench-hardened layer, a grain size number of prior austenite crystal grains being No. 11 or higher.2. The mechanical component according to claim 1 , wherein the quench-hardened layer has a thickness of more than or equal to 4 mm.3. The mechanical component according to claim 1 , wherein the quench-hardened layer has a Vickers hardness of more than or equal to 500 HV. The present invention relates to a mechanical component, more particularly, a mechanical component having a hardened layer formed in a surface layer of the mechanical component.An ECAP (Equal Channel Angular Processing) method is a representative method for applying large strain to a metal material. The ECAP method is drawing attention as a large-strain processing method with which the shape of a material is not much changed before and after the processing. However, in the ECAP method, an amount of strain in one processing is not so large. Therefore, in the ECAP method, the processing has to be performed multiple times in order to exhibit desired fine crystal grains and ...

ELECTRIC RESISTANCE WELDED CLAD STEEL PIPE OR TUBE AND METHOD OF PRODUCING SAME

Provided is an electric resistance welded clad steel pipe or tube in which a region where solidification microstructure is formed, i.e. a region in a weld particularly having significant influence on properties, is reduced without impairing its function as a clad pipe or tube. An electric resistance welded clad steel pipe or tube comprises: a first layer made of carbon steel or low-alloy steel as base metal; and a second layer placed on one surface of the first layer, and made of stainless steel or a nickel-containing alloy as cladding metal, wherein the base metal is not exposed at a cladding metal-side surface of the electric resistance welded clad steel pipe or tube in a weld, and no solidification microstructure is contained in each of circular sections of 0.1 mm in radius respectively centered at specific three positions in a plane perpendicular to a pipe or tube longitudinal direction. 119.-. (canceled)20. An electric resistance welded clad steel pipe or tube , comprising:a first layer made of carbon steel or low-alloy steel as base metal; anda second layer placed on one surface of the first layer, and made of stainless steel or a nickel-containing alloy as cladding metal,wherein the base metal is not exposed at a cladding metal-side surface of the electric resistance welded clad steel pipe or tube in a weld, andno solidification microstructure is contained in each of circular sections of 0.1 mm in radius respectively centered at the following positions (i) to (iii) in a plane perpendicular to a pipe or tube longitudinal direction:(i) a position that is 1 mm in depth from an outer surface of the electric resistance welded clad steel pipe or tube in the weld and is 0.3 mm in a transverse direction of weld metal from a center of a width of the weld metal in a pipe or tube circumferential direction;(ii) a position that is a center of the electric resistance welded clad steel pipe or tube in a thickness direction in the weld and is 0.3 mm in the transverse ...

QUENCHING APPARATUS AND METHOD FOR PRODUCING METALLIC MATERIAL

A circulation apparatus recovers cooling fluid after the cooling fluid is used for quenching and supplies the cooling fluid to a defoaming bath. A laminar flow weir of a defoaming apparatus partitions the defoaming bath into laminar and shallow flow baths. The laminar flow weir is lower than a side wall of the laminar flow bath. Cooling fluid from the circulation apparatus is supplied to the laminar flow bath and the cooling fluid is poured into the shallow bath from the laminar flow bath along the laminar flow weir. A filter covers an opening in a bottom portion of the shallow bath. The liquid level height in the shallow bath is less than the height of the laminar flow weir. A supply bath accumulates cooling fluid that passes through the filter, and supplies the cooling fluid to a cooling apparatus that sprays the cooling fluid onto a metallic material. 1. A quenching apparatus that sprays a cooling fluid to quench a metallic material , comprising:a defoaming apparatus that removes air bubbles from the cooling fluid,a supply bath that accumulates the cooling fluid that air bubbles has been removed, anda cooling apparatus that sprays the cooling fluid that has been supplied from the supply bath toward the metallic material;the defoaming apparatus comprising:a defoaming bath, anda circulation apparatus that recovers the cooling fluid that has been used for quenching, and supplies the cooling fluid to the defoaming bath;wherein:the defoaming bath includes a laminar flow weir that partitions the defoaming bath into a laminar flow bath and a shallow bath, in that the laminar flow weir is lower than a side wall of the laminar flow bath, andthe cooling fluid from the circulation apparatus is supplied to the laminar flow bath, and the cooling fluid that flows over the laminar flow weir from the laminar flow bath is poured into the shallow bath,the shallow bath including:a bottom portion having an opening, anda plate-shaped or sheet-shaped filter that covers the opening and ...

DEVICE FOR TREATING, BY HEAT TEMPERING, A METAL ELEMENT OF THE TUBE OR BAR TYPE HAVING ARCHED PORTIONS

The invention relates to a device for treating, by heat tempering, a metal element () of the tube or bar type having arched portions. The device includes heat treatment means having an induction coil () and a sprinkler ring (). According to the invention, this device includes means () for holding the metal element () that is composed of a clip () arranged so as to clamp around an end portion, referred to as the top, of the metal element and to keep the metal element freely suspended under said clip. The device also includes multi-axis robots () suitable for moving the induction coil () and the sprinkler ring () simultaneously along the metal element () starting from an end portion, referred to as the bottom, of the metal element that is opposite the top portion thereof. 1. A thermal quenching treatment device of a metal element , of the tube or bar type , having curved sections , comprising:a heat treatment device comprising an induction coil and a cooling device comprising spray nozzles integrated into an annular sprinkler ring,a holding device for the metal element,and a displacement device, the holding device and the heat treatment device are adapted to produce a relative displacement of the metal element inside the induction coil, and the annular sprinkler ring is arranged in close proximity to both the holding device and the heat treatment device,the holding device for maintaining the metal element is composed of a clamp arranged in such a way as to tighten a stretch of an end of the metal element, and to maintain the metal element freely suspended under the clamp, and there is provided a travel device that is capable of simultaneously moving the induction coil and the annular sprinkler ring along the metal element suspended under the clamp, from an end section of the metal element opposite to an upper section.2. The thermal quenching treatment device according to claim 1 , wherein the clamp retaining the metal element is carried by a rotational drive of the ...

HIGH CHROMIUM MARTENSITIC HEAT-RESISTANT STEEL WITH COMBINED HIGH CREEP RUPTURE STRENGTH AND OXIDATION RESISTANCE

Provided is martensitic heat-resistant steel for boiler applications with a unique combination of enhanced creep strength and excellent oxidation resistance upon high temperature exposure in steam containing environments contacts (in wt.-%): C: 0.10 to 0.16%, Si: 0.20 to 0.60%, Mn: 0.30 to 0.80%, P≤0.020%, S≤0.010%, Al≤0.020%, Cr: 10.5 to 12.00%, Mo: 0.10 to 0.60%, V: 0.15 to 0.30%, Ni: 0.10 to 0.40%, B: 0.008 to 0.015%, N:0.002 to 0.020%, Co: 1.50 to 3.00%, W: 1.50 to 2.50%, Nb: 0.02 to 0.07%, Ti: 0.001-0.020%, iron and unavoidable impurities. The steel is normalized for about 10 to about 120 minutes at a temperature of 1050-1170° C. and cooled down in air or water to room temperature, and then tempered for at least one hour at a temperature of 750-820° C. The steel has a martensitic microstructure with average δ-ferrite content of less than 5 vol.-%. 1. A seamless tubular product , made of a steel comprising , in weight percent:C: 0.10 to 0.16%,Si: 0.20 to 0.60%,Mn: 0.30 to 0.80%,P≤0.020%,S≤0.010%,Al≤0.020%,Cr: 10.50 to 12.00%,Mo: 0.10 to 0.60%,V: 0.15 to 0.30%,Ni: 0.10 to 0.40%,B: 0.008 to 0.015%,N: 0.002 to 0.020%,Co: 1.50 to 3.00%,W: 1.50 to 2.50%,Nb: 0.02 to 0.07%,Ti: 0.001 to 0.020%,iron and unavoidable impurities.2. The seamless tubular product according to claim 1 , wherein: B/N≤1.5.3. The seamless tubular product according to claim 1 , wherein claim 1 , the contents of Mo and W in wt % satisfy:{'br': None, '1.00%≤Mo+0.5W≤1.50%.'}4. The seamless tubular product according to claim 1 , wherein the contents of B claim 1 , N claim 1 , and Ti in wt % satisfy:{'br': None, 'sup': '−(1/2.45)·(log B+6.81)', 'B−(11/14)(N−10−(14/48)·Ti)≥0.007.'}5. The seamless tubular product according to claim 1 , wherein claim 1 , the contents of Ni claim 1 , Co claim 1 , Mn claim 1 , C claim 1 , and N in wt.-% satisfy:{'br': None, '2.6≤4·(Ni+Co+0.5·Mn)−20·(C+N)≤11.2.'}6. The seamless tubular product according to claim 1 , wherein the carbon content is between 0.13 and 0.16%.7. The ...

ULTRA-HIGH TOUGHNESS AND HIGH STRENGTH DRILL PIPE AND MANUFACTURING PROCESS THEREOF

The invention discloses a drill pipe having ultra-high toughness and high strength and comprising the following chemical elements in mass percentage: C: 0.24-0.30%, Si: 0.1-0.5%, Mn: 0.7-1.5%, Cr: 0.7-1.5%, Mo: 0.5-0.75%, V: 0.01-0.10%, Nb: 0.01-0.05%, P≦0.015% , S≦0.005%, and the balance of Fe and unavoidable impurities; and a process of manufacturing the drill pipe having ultra-high toughness and high strength, comprising: heating the drill pipe as a whole to 900-950° C.; subjecting the inner surface of the drill pipe to axial-flow water-spray cooling and the outer surface of the drill pipe to laminar-flow water-spray cooling while controlling the amount of the water sprayed at thickened ends of the drill pipe and that along the pipe body to be different from each other; and controlling the tempering temperature to be 650-675° C. The inventive drill pipe having ultra-high toughness and high strength has a longitudinal full-size impact toughness at −20° C. of at least 100 J and has a strength of 135 ksi. 1. A drill pipe having ultra-high toughness and high strength , and comprising the following chemical elements in mass percentage:C: 0.24-0.30%, Si: 0.1-0.5%, Mn: 0.7-1.5%, Cr: 0.7-1.5%, Mo: 0.5-0.75%, V: 0.01-0.10%, Nb: 0.01-0.05%, P<0.015%, S<0.005%, and the balance of Fe and unavoidable impurities.2. The drill pipe having ultra-high toughness and high strength according to claim 1 , wherein the mass percentages of the chemical elements are:C: 0.25-0.29%, Si : 0.24-0.38%, Mn : 0.92-1.17%, Cr : 0.95-1.22%, Mo : 0.6-0.75%, V : 0.05-0.09%, Nb : 0.02-0.04%, P<0.015%, S<0.005%, and the balance of Fe and unavoidable impurities.3. The drill pipe having ultra-high toughness and high strength according to claim 1 , wherein the mass percentages of the chemical elements are:C: 0.26-0.28%, Si: 0.27-0.36%, Mn: 0.70-1.17%, Cr: 0.95-1.22%, Mo: 0.61-0.72%, V: 0.05-0.08%, Nb: 0.02-0.04%, P<0.015%, S<0.005%, and the balance of Fe and unavoidable impurities.4. The drill pipe having ...

Steel pipe or tube for pressure vessels, method of producing steel pipe or tube for pressure vessels, and composite pressure vessel liner

A steel pipe or tube for pressure vessels having excellent quench crack resistance is provided. The steel pipe or tube for pressure vessels comprises: a specific chemical composition; and a metallic microstructure in which an average grain size of prior austenite grains is 500 μm or less, and an area fraction of microstructures other than ferrite is 50% or more.

METHOD FOR PRODUCING A RE-SHAPED COMPONENT FROM A MANGANESE-CONTAINING FLAT STEEL PRODUCT AND SUCH A COMPONENT

The invention relates to a method for producing a component from a medium manganese flat steel product having 4 to less than 10 wt. % Mn, 0.0005 to 0.9 wt. % C, 0.02 to 10 wt. % Al, the remainder iron, including unavoidable steel-accompanying elements, and having a TRIP effect at room temperature. In order to produce a component, which is distinguished by very high strengths and an increased residual strain and re-shaping capacity, the flat steel product, according to the invention, is re-shaped by at least one re-shaping step to form a component and, before and/or during and/or after the at least one re-shaping step, the flat steel product is cooled down to a temperature of the flat steel product of less than room temperature to −196° C. The invention further relates to a component produced by this method and to a use for said components. 117-. (canceled)18. A method for producing a component of a medium manganese fiat steel product comprising 4 to less than 10 wt. % Mn , 0.0005 to 0.9 wt. % C , 0.02 to 10 wt. % Al , with the remainder being iron including unavoidable steel-associated elements and with a TRIP effect at room temperature , said method comprising:deforming the flat steel product to form a component by at least one deforming step; andcooling the flat steel product prior to and/or during and/or after the at least one deforming step to a temperature of the flat steel product of less than room temperature to −196° C.19. The method of claim 18 , wherein the flat steel product is deformed to form the component in the at least one deforming step at a temperature of the flat steel product of less than room temperature to −196° C. claim 18 , preferably less than 0° C. to −196° C.20. The method of claim 18 , wherein the flat steel product is cooled claim 18 , prior to the at least one deforming step claim 18 , to a temperature of less than room temperature to −196° C. claim 18 , preferably less than 0° C. to −196° C.21. The method of claim 18 , wherein the at ...

Ultra High Strength Alloy for Severe Oil and Gas Environments and Method of Preparation

A high strength, corrosion resistant alloy suitable for use in oil and gas environments includes, in weight percent: 0-15% Fe, 18-24% Cr, 3-9% Mo, 0.05-3.0% Cu, 4.0-6.5% Nb, 0.5-2.2% Ti, 0.05-1.0% Al, 0.005-0.040% C, balance Ni plus incidental impurities and deoxidizers. A ratio of Nb/(Ti+Al) is equal to 2.5-7.5.

REGENERATIVE HEAT TREATMENT METHOD FOR HEAT-RESISTANT METAL MEMBER SUFFERING FROM CREEP DAMAGE

A heat-resistant metal member suffering from creep damage is covered by a heat-resistant covering member and secured so as to contact an outer periphery of the heat-resistant metal member, and the heat-resistant metal member covered by the heat-resistant covering member is heated to a temperature of 1000° C. or greater. A compressive force accordingly acts on the heat-resistant metal member undergoing thermal expansion toward the outer periphery, enabling efficient regenerative heat treatment to be performed on the heat-resistant metal member suffering from creep damage, while restraining thermal expansion in the direction toward the outer periphery of the heat-resistant metal member. 1. A regenerative heat treatment method for a heat-resistant metal member suffering from creep damage , the method comprising:covering the heat-resistant metal member by a heat-resistant covering member and securing so as to contact an outer periphery of the heat-resistant metal member; andheating the heat-resistant metal member covered by the heat-resistant covering member to a temperature of 1000° C. or greater.2. The method according to claim 1 , wherein claim 1 ,{'sub': '1', 'after heating the heat-resistant metal member covered by the heat-resistant covering member to a temperature of 1000° C. or greater, the heat-resistant metal member covered by the heat-resistant covering member is cooled and re-heated to a temperature of an Atransformation point or greater.'} The present invention relates to a regenerative heat treatment method for a heat-resistant metal member suffering from creep damage.Hitherto, as a method to regenerate locations degraded by creep damage in high temperature members, such as those employed in thermal or nuclear power plants, or chemical plants (for example, high temperature resistant welds of boilers and turbines, and base material for high temperature pipes, headers, nozzles and the like), a method has been developed in which, for example, the high ...

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;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 of the coiled steel tube comprises more than 90 volume % tempered martensite and 0 volume % to less than about 10 volume % bainite 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;wherein the hardness is substantially uniform along substantially all of the length of the coiled steel tube that is adapted to be inserted into a wellbore; andwherein the yield strength following manufacture of the coiled steel tube is at least about 80 ksi.24. The coiled steel tube of claim 23 , wherein the tube has a yield strength of at least 110 ksi.25. The coiled steel tube of claim 23 , wherein the tube has a yield strength of at least 125 ksi.26. The coiled steel tube of claim 23 , wherein a length of the coiled steel tube is not adapted to be inserted into a wellbore.27. The coiled steel tube of claim 23 , wherein the length of the coiled steel ...

High-strength stainless steel seamless pipe for oil country tubular goods, and method for manufacturing same

The invention is intended to provide a high-strength stainless steel seamless pipe for oil country tubular goods having high strength with a yield strength of 862 MPa (125 ksi) or more, excellent low-temperature toughness, and excellent corrosion resistance. The invention is also intended to provide a method for manufacturing such a high-strength stainless steel seamless pipe. The high-strength stainless steel seamless pipe has a microstructure that is at least 45% tempered martensite phase, 20 to 40% ferrite phase, and more than 10% and 25% or less retained austenite phase by volume. The high-strength stainless steel seamless pipe has a yield strength of 862 MPa or more, and a maximum crystal grain diameter of 500 μm or less for ferrite crystal grains when crystal grains with a crystal orientation difference of within 15° are defined as the same crystal grains.

LIGHTWEIGHT BORON TUBULAR STRUCTURE SUPPORT INTEGRATED INTO SEAT STRUCTURE

A support may include a hollow metallic tube having two opposing ends and a body extending over a longitudinal axis of the tube. The tube may have a steel composition that may include, by weight, the following concentrations: approximately 0.19 to 0.27% carbon; approximately 0.0005% to 0.004% boron; approximately 1.5% to 2.5% manganese; and less than or equal to approximately 0.35% chromium, the balance including iron and inevitable impurities. 1. A support , comprising: approximately 0.19 to 0.27% carbon;', 'approximately 0.0005% to 0.004% boron;', 'approximately 1.5% to 2.5% manganese; and', 'less than or equal to approximately 0.35% chromium, the balance including iron and inevitable impurities., 'a hollow metallic tube having two opposing ends and a body extending over a longitudinal axis of the tube, wherein the tube has a steel composition including, by weight, the following concentrations2. The support of claim 1 , wherein the tube has a yield strength of 1170-1300 MPa.3. The support of claim 1 , wherein the tube has a tensile strength greater than 1475 MPa.4. The support of claim 1 , wherein the tube has an elongation of at least 10%.5. The support of claim 1 , wherein the tube has a specific strength of 180-195 kN·m/kg.6. The support of claim 1 , wherein the steel composition is quenched at a cooling rate of at least 27 K/s.7. The support of claim 1 , wherein the tube is integrated into a seat frame.8. A support integrated into a seat structure of a vehicle claim 1 , comprising: approximately 0.19% to 0.27% carbon;', 'approximately 0.0005% to 0.004% boron;', 'approximately 1.5% to 2.5% manganese; and', 'less than or equal to about 0.35% chromium, the balance including iron and inevitable impurities., 'a hollow metallic tube having two opposing ends and a body extending over a longitudinal axis of the tube, wherein the tube includes an austenitized steel composition having a martensite microstructure via quenching, the steel composition including, by weight, ...

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. 110-. (canceled)11. Steel material for composite pressure vessel liners , comprising: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%, andAl: 0.01% to 0.06%, with a balance being Fe and incidental impurities; anda 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.12. The steel material for composite pressure vessel liners according to claim 11 ,wherein the chemical composition further contains, in mass %, one or both of Mo: 0.005% to 2.0% and Cr: 0.005% to 3.0%.13. The steel material for composite pressure vessel liners according to claim 12 ,wherein the chemical composition further contains, in mass%, Ni: 0.005% to 3.0%.14. The steel material for composite pressure vessel liners according to claim 11 , {'br': None, '[Mn]+1.30×[Cr]+2.67×[Mo]+0.30×[Ni]≥2.30 \u2003\u2003(1)'}, 'wherein the chemical composition satisfies a relationship of the following Expression (1)where [M] denotes a content of element M in mass %, and [M]=0 in the case where the element M is not contained.15. The steel ...

HIGH-STRENGTH SEAMLESS STEEL PIPE FOR OIL COUNTRY TUBULAR GOODS, AND METHOD FOR PRODUCING THE SAME

Provided herein is a high-strength seamless steel pipe containing a particular chemical composition. The volume fraction of tempered martensite is 90% or more in terms of a volume fraction. The number of nitride inclusions with a particle diameter of 4 μm or more is 50 or less per 100 mm, the number of nitride inclusions with a particle diameter of less than 4 μm is 500 or less per 100 mm, the number of oxide inclusions with a particle diameter of 4 μm or more is 40 or less per 100 mm, and the number of oxide inclusions with a particle diameter of less than 4 μm is 400 or less per 100 mmin a cross section perpendicular to a rolling direction. 16-. (canceled)7. A high-strength seamless steel pipe for oil country tubular goods , the high-strength seamless steel pipe having a composition that comprises , in mass % , C: 0.20 to 0.50% , Si: 0.05 to 0.40% , Mn: 0.3 to 0.9% , P: 0.015% or less , S: 0.005% or less , Al: 0.03 to 0.1% , N: 0.006% or less , Cr: more than 0.6% and 1.7% or less , Mo: more than 1.0% and 3.0% or less , V: 0.02 to 0.3% , Nb: 0.001 to 0.02% , B: 0.0005 to 0.0040% , O (oxygen): 0.0030% or less , Ti: less than 0.003% , and the balance being Fe and unavoidable impurities ,{'sup': 2', '2', '2', '2, 'the high-strength seamless steel pipe having a structure in which the volume fraction of tempered martensite is 90% or more, and in which the number of nitride inclusions with a particle diameter of 4 μm or more is 50 or less per 100 mm, the number of nitride inclusions with a particle diameter of less than 4 μm is 500 or less per 100 mm, the number of oxide inclusions with a particle diameter of 4 μm or more is 40 or less per 100 mm, and the number of oxide inclusions with a particle diameter of less than 4 μm is 400 or less per 100 mmin a cross section perpendicular to a rolling direction,'}the high-strength seamless steel pipe having a yield stress YS of 862 MPa or more.8. The high-strength seamless steel pipe for oil country tubular goods according to ...

METHOD FOR MANUFACTURING HEAVY WALL STEEL PIPE

A method for manufacturing a heavy wall steel pipe includes a cooling step in which a steel pipe, with a wall thickness of ½ inch or more, that has been heated to the gamma range is dipped in water while supporting and rotating the steel pipe about the axis of pipe, an axial stream which is a water flow in the direction of axis of pipe is applied to the inside surface of the steel pipe under rotation in the water, and an impinging stream which is a water flow impinging on the outer surface of the pipe is applied to the outer surface of the steel pipe under rotation in the water. 1. A method for manufacturing a heavy wall steel pipe , the method comprising:dipping a steel pipe having a wall thickness of ½ inch or more in water, the steel pipe having been heated to the gamma range, the dipping including supporting and rotating the steel pipe about the axis of the steel pipe at a circumferential velocity of pipe of 4 m/s or more;applying an axial stream comprising a water flow in the direction of an axis of the steel pipe to the inside surface of the steel pipe under rotation in the water, the pipe flow velocity of the axial stream is set at 7 m/s or more; andapplying an impinging stream which comprising a water flow impinging on the outer surface of the steel pipe to the outer surface of the steel pipe under rotation in the water, the discharge flow velocity of the impinging stream is set at 9 m/s or more, whereinthe application of the axial stream and the impinging stream are started within 1.1 s after the entire steel pipe is dipped in the water and continued until the temperature of the steel pipe is decreased to 150° C. or lower.2. The method for manufacturing a heavy wall steel pipe according to claim 1 , wherein the wall thickness is in the range of ½ inch to 2 inches.3. The method for manufacturing a heavy wall steel pipe according to claim 1 , wherein a temperature of the dipping water is in the range of 50° C. or less.4. The method for manufacturing a heavy ...

STEEL MATERIAL AND METHOD FOR PRODUCING STEEL MATERIAL

The 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 0.60 to 1.80%, Mo: 0.80 to 2.30%, Ti: 0.002 to 0.020%, V: 0.05 to 0.30%, Nb: 0.002 to 0.100%, B: 0.0005 to 0.0040%, Cu: 0.01 to 0.50%, Ni: 0.01 to 0.50%, N: 0.0020 to 0.0100% and O: 0.0020% or less, with the balance being Fe and impurities. The number density of BN in the steel material is 10 to 100 particles/100 μm. The yield strength of the steel material is 758 MPa or more. 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: 0.60 to 1.80%,Mo: 0.80 to 2.30%,Ti: 0.002 to 0.020%,V: 0.05 to 0.30%,Nb: 0.002 to 0.100%,B: 0.0005 to 0.0040%,Cu: 0.01 to 0.50%,Ni: 0.01 to 0.50%,N: 0.0020 to 0.0100%,O: 0.0020% or less,Ca: 0 to 0.0100%,Mg: 0 to 0.0100%,Zr 0 to 0.0100%,rare earth metal: 0 to 0.0100%,Co: 0 to 0.50%, andW: 0 to 0.50%,with the balance being Fe and impurities,wherein{'sup': '2', 'in the steel material, a number density of BN is within a range of 10 to 100 particles/100 μm, and'}a yield strength is 758 MPa or more.8. The steel material according to claim 7 , wherein the chemical composition contains one or more types of element selected from the group consisting of:Ca: 0.0001 to 0.0100%,Mg: 0.0001 to 0.0100%,Zr 0.0001 to 0.0100%, andrare earth metal: 0.0001 to 0.0100%.9. The steel material according to claim 7 , wherein the chemical composition contains one or more types of element selected from the group consisting of:Co: 0.02 to 0.50%, andW: 0.02 to 0.50%.10. The steel material according to claim 8 , wherein the chemical composition contains one or more types of element selected from the group consisting of:Co: 0.02 to 0.50%, andW: 0.02 to 0.50%.11. The steel material according to claim ...

STAINLESS STEEL PIPE AND METHOD OF MANUFACTURING THE SAME

A stainless steel pipe has a composition of, in mass %: C: up to 0.02%; Si: 0.05 to 1.00%; Mn: 0.1 to 1.0%; P: up to 0.030%; S: up to 0.002%; Ni: 5.5 to 8%; Cr: 10 to 14%; Mo: 2 to 4%; V: 0.01 to 0.10%; Ti: 0.05 to 0.3%; Nb: up to 0.1%; Al: 0.001 to 0.1%; N: up to 0.05%; Cu: up to 0.5%; Ca: 0 to 0.008%; Mg: 0 to 0.05%; B: 0 to 0.005%; and balance Fe and impurities. The pipe having a microstructure including martensite and, by volume fraction, 12 to 18% retained austenite. The martensite has prior austenite grains of a crystal grain size number lower than 8.0 in accordance with ASTM E112. The stainless steel pipe has a yield strength of 550 to 700 MPa. 1. A stainless steel pipe having a chemical composition of , in mass %:C: up to 0.02%;Si: 0.05 to 1.00%;Mn: 0.1 to 1.0%;P: up to 0.030%;S: up to 0.002%;Ni: 5.5 to 8%;Cr: 10 to 14%;Mo: 2 to 4%;V: 0.01 to 0.10%;Ti: 0.05 to 0.3%;Nb: up to 0.1%;Al: 0.001 to 0.1%;N: up to 0.05%;Cu: up to 0.5%;Ca: 0 to 0.008%;Mg: 0 to 0.05%;B: 0 to 0.005%; andbalance Fe and impurities,the stainless steel pipe having a microstructure including martensite and, by volume fraction, 12 to 18% retained austenite,the martensite having prior austenite grains of a crystal grain size number lower than 8.0 in accordance with ASTM E112,the stainless steel pipe having a yield strength of 550 to 700 MPa.2. The stainless steel pipe according to claim 1 , wherein the chemical composition includes one or more elements selected from the group consisting of claim 1 , in mass %:Ca: 0.001 to 0.008%;Mg: 0.001 to 0.05%; andB: 0.0005 to 0.005%.3. A method of manufacturing a stainless steel pipe comprising:hot-working a steel material having a chemical composition of, in mass %; C: up to 0.02%; Si: 0.05 to 1.00%; Mn: 0.1 to 1.0%; P: up to 0.030% S: up to 0.002%; Ni: 5.5 to 8%; Cr: 10 to 14%; Mo: 2 to 4%; V: 0.01 to 0.10%; Ti: 0.05 to 0.3%; Nb: up to 0.1%; Al: 0.001 to 0.1%; N: up to 0.05%; Cu: up to 0.5%; Ca: 0 to 0.008%; Mg: 0 to 0.05%; B: 0 to 0.005%; and balance ...

ELECTRIC RESISTANCE WELDED STEEL TUBES FOR HIGH-STRENGTH THIN HOLLOW STABILIZERS, AND METHODS FOR MANUFACTURING THE SAME

A method for manufacturing an electric resistance welded steel tube for high-strength thin hollow stabilizers is provided. A steel with a certain chemical composition is heated to a temperature of 1000 to 1300° C., hot rolled under conditions where the rolling finish temperature is 750 to 950° C., cooled, coiled into a coil at 500 to 650° C., and skin pass rolled with a rolling reduction ratio of not less than 0.3%. The resultant hot rolled sheet is electric resistance welded into an electric resistance welded steel tube, which is then reheated to a temperature of 800 to 1100° C. and hot stretch-reducing rolled under conditions where the rolling finish temperature is not more than 850° C. and the cumulative diameter reduction is not more than 75%. Consequently, a thin electric resistance welded steel tube is produced. 1. A method for manufacturing an electric resistance welded steel tube for high-strength thin hollow stabilizers , comprising heating , hot rolling and skin pass rolling processes where a steel is formed into a hot rolled sheet , a tube making process by an electric resistance welding is applied to the hot rolled sheet as a steel tube material into an electric resistance welded steel tube , and a hot stretch-reducing rolling process is applied to the reheated and hot stretch-reducing rolled electric resistance welded steel tube , making a product tube having a reduced diameter , wherein C: 0.20 to 0.40%, Si: 0.1 to 1.0%,', 'Mn: 0.1 to 2.0%, P: not more than 0.1%,', 'S: not more than 0.01%, Al: 0.01 to 0.10%,', 'Cr: 0.01 to 1.0%, Ti: 0.01 to 0.05%,', 'B: 0.0005 to 0.0050%, Ca: 0.0001 to 0.0050%, and', 'N: not more than 0.010%, the balance being Fe and inevitable impurities,, 'the steel has a chemical composition comprising, in mass %the heating process for the steel comprises heating the steel to a heating temperature in the range of 1000 to 1300° C.,the hot rolling process comprises hot rolling the steel under conditions where the rolling finish ...

MARTENSITIC STAINLESS STEEL SEAMLESS PIPE FOR OIL COUNTRY TUBULAR GOODS, AND METHOD FOR PRODUCING SAME

Provided herein is a martensitic stainless steel seamless pipe, intended for oil country tubular goods, having high strength, and excellent sulfide stress corrosion cracking resistance. A method for producing such a martensitic stainless steel seamless pipe is also provided. The martensitic stainless steel seamless pipe for oil country tubular goods has a composition that contains, in mass %, C: 0.035% or less, Si: 0.5% or less, Mn: 0.05 to 0.5%, P: 0.03% or less, S: 0.005% or less, Cu: 2.6% or less, Ni: 5.3 to 7.3%, Cr: 11.8 to 14.5%, Al: 0.1% or less, Mo: 1.8 to 3.0%, V: 0.2% or less, N: 0.1% or less, and the balance Fe and unavoidable impurities, and in which C, Mn, Cr, Cu, Ni, Mo, W, Nb, N, and Ti satisfy the predetermined relations. 1. A martensitic stainless steel seamless pipe for oil country tubular goods ,the martensitic stainless steel seamless pipe having a composition that comprises, in mass %, C: 0.035% or less, Si: 0.5% or less, Mn: 0.05 to 0.5%, P: 0.03% or less, S: 0.005% or less, Cu: 2.6% or less, Ni: 5.3 to 7.3%, Cr: 11.8 to 14.5%, Al: 0.1% or less, Mo: 1.8 to 3.0%, V: 0.2% or less, N: 0.1% or less, and the balance Fe and unavoidable impurities, and that satisfies the following formula (4) with the following formulae (1), (2), and (3), [{'br': None, '−109.37C+7.307Mn+6.399Cr+6.329Cu+11.343Ni−13.529Mo+1.276W+2.925Nb+196.775N−2.621Ti−120.307\u2003\u2003Formula (1)'}, {'br': None, '−0.0278Mn+0.0892Cr+0.00567Ni+0.153Mo−0.0219W−1.984N+0.208Ti−1.83\u2003\u2003 Formula (2)'}, {'br': None, '−1.324C+0.0533Mn+0.0268Cr+0.0893Cu+0.00526Ni+0.0222Mo−0.0132W−0.473N−0.5Ti−0.514,\u2003\u2003Formula (3)'}], 'the martensitic stainless steel seamless pipe having a yield stress of 758 MPa or more.'} {'br': None, '−10≤formula (1)≤45, −0.25≤formula (2)≤−0.20, and 0.10≤formula (3)≤0.20\u2003\u2003Formula (4)'}, 'In the formulae (1) to (3), C, Mn, Cr, Cu, Ni, Mo, W, Nb, N, and Ti represent the content of each element in mass % (the content being 0 (zero) percent for ...

EQUIPMENT LINE FOR MANUFACTURING SEAMLESS STEEL TUBE OR PIPE AND METHOD OF MANUFACTURING HIGH-STRENGTH STAINLESS STEEL SEAMLESS TUBE OR PIPE FOR OIL WELLS USING THE EQUIPMENT LINE

An equipment line for manufacturing a seamless steel tube includes a steel heating device, a piercing device that pierces the steel into a hollow steel tube, a rolling mill that forms the hollow steel tube into a seamless steel tube having a predetermined shape, and a cooling system arranged between the heating device and the piercing device or between the piercing device and the rolling mill. 16.-. (canceled)7. An equipment line for manufacturing a seamless steel tube comprising:a steel heating device,a piercing device that pierces the steel into a hollow steel tube,a rolling mill that forms the hollow steel tube into a seamless steel tube having a predetermined shape, anda cooling system arranged between the heating device and the piercing device or between the piercing device and the rolling mill.8. The equipment line according to claim 7 , wherein the cooling system has a cooling capacity that cools an outer surface of steel at an average cooling rate of 1.0° C./s or more.9. The equipment line according to claim 7 , further comprising a thermostat arranged on an exit side of the rolling mill.10. A method of manufacturing a high-strength stainless seamless steel tube with the equipment line according to claim 7 , comprising;heating steel in the heating device,piercing the steel in the piercing device into a hollow steel tube,cooling the hollow steel tube in the cooling system, andforming the hollow steel tube in the rolling mill into a seamless steel tube having a predetermined size, orfurther passing the seamless steel tube through a thermostat,wherein the steel has a chemical composition consisting of by mass %, 0.050% or less C, 0.50% or less Si, 0.20 to 1.80% Mn, 15.5 to 18.0% Cr, 1.5 to 5.0% Ni, 1.0 to 3.5% Mo, 0.02 to 0.20% V, 0.01 to 0.15% N, 0.006% or less O, and Fe and unavoidable impurities as a balance, the heating in the heating device is performed such that the steel is heated to a temperature within a range from 600° C. to a temperature below a ...

Seamless steel pipe suitable for use in sour environment

The seamless steel pipe 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 0.070%, Cr: 0.30 to 1.50%, Mo: 0.25 to 2.00%, Ti: 0.002 to 0.020%, Nb: 0.002 to 0.100%, B: 0.0005 to 0.0040%, rare earth metal: 0.0001 to 0.0015%, Ca: 0.0001 to 0.0100%, N: 0.0100% or less and O: 0.0020% or less, with the balance being Fe and impurities, and satisfying Formula (1) described in the description. A predicted maximum major axis of inclusions is 150 μm or less, the predicted maximum major axis being predicted by means of extreme value statistical processing. The yield strength is within a range of 758 to 862 MPa.

METHODS FOR QUENCHING METAL TUBES

Improved methods for quenching a metal tube are disclosed. A method of manufacturing a metal tube generally comprises solution heat treating a metal tube at an elevated temperature, rapidly cooling the metal tube from the elevated temperature, raising the open end of the metal tube to an elevated position, and lowering the open end of the metal tube to a downward facing position, wherein the metal tube comprises an open end and an opposing closed end, wherein the immersing step comprises at least partially filling the metal tube with the cooling liquid, and developing an evolved gas inside the metal tube, wherein the raising comprises releasing at least some of the evolved gas from the metal tube via the open end, and wherein the lowering comprises draining cooling liquid from the metal tube via the open end.

PROCESS FOR ON-LINE QUENCHING OF SEAMLESS STEEL TUBE USING RESIDUAL HEAT AND MANUFACTURING METHOD

An process for the on-line quenching of seamless steel tube using residual heat, a method for manufacturing a seamless steel tube, and a seamless steel tube. The process for the on-line quenching of a seamless steel tube comprises the following steps: when the temperature of a tube is higher than Ar3, evenly spraying water along a circumferential direction of the tube so as to continuously cool the tube to be not higher than T° C., the cooling rate being controlled to be E1° C./s to E2° C./s to obtain a microstructure with martensite as the main composition, wherein T=Ms−95° C., Ms represents the martensitic phase transition temperature, E1=20×(0.5−C)+15×(3.2−Mn)−8×Cr−28×Mo−4×Ni−2800×B, and E2=96×(0.45−C)+12×(4.6−Mn), and the C, Mn, Cr, Ni, B and Mo in the equations each represents the mass percentages of corresponding elements in the seamless steel tube. 2. The process for the on-line quenching of seamless steel tube according to claim 1 , wherein the total amount of alloying elements of the seamless steel tube is not more than 5% by mass claim 1 , said alloying elements being at least one selected from C claim 1 , Mn claim 1 , Cr claim 1 , Mo claim 1 , Ni claim 1 , Cu claim 1 , V claim 1 , Nb and Ti.3. The process for the on-line quenching of seamless steel tube according to claim 2 , wherein the total amount of alloying elements of the seamless steel tube is 0.2% to 5% by mass.4. The process for the on-line quenching of seamless steel tube according to claim 1 , wherein the phase ratio of martensite is not less than 9.0%.5. A method for manufacturing a seamless steel tube using residual heat claim 1 , comprising the following steps:(1) manufacturing the billet;(2) forming the billet into tube;{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, '(3) cooling the tube by the process for the on-line quenching of seamless steel tube according to ; and'}(4) tempering.6. The method for manufacturing seamless steel tube according to claim 5 , wherein in the step (4) claim ...

INDUCTION HEATING COIL, AND AN APPARATUS AND METHOD FOR MANUFACTURING A WORKED MEMBER

An induction heating coil for stably heating a steel tube which is being fed in its axial direction without rotating, the heating being uniform in the circumferential direction and in a narrow range in the axial direction has at least two 1-turn coils in the form of a first turn coil body and a second turn coil body. The inner peripheral length Ln (the non-effective coil length) where the effective number of coil turns is less than the total number of coil turns when the coil is projected in the axial direction and the inner peripheral length LO of the projected coil bodies (the inner coil length) satisfy Ln/LO <0.05. First and second coil bodies have insulating portions on their connecting portions, and the insulating portions are present in locations separated by a central angle of 5-45° measured from the center of the coil bodies. 13-. (canceled)4. A method of manufacturing a worked member characterized by performing induction heating of an elongated metal material which is not rotating about its central axis using an induction heating coil while carrying out relative movement of the induction heating coil in the axial direction of the metal material with respect to the metal material , cooling the metal material which underwent induction heating by the induction heating coil with a cooling mechanism which undergoes relative movement with respect to the metal material together with the induction heating coil , thereby forming a high temperature portion in the metal material which moves in the axial direction of the metal material , and then applying a bending moment to the high temperature portion of the metal material , wherein the induction heating coil comprises at least a first 1-turn coil body which surrounds an outer periphery of the metal material in a circumferential direction and is spaced from the metal material and which has a first electrically insulating portion and a first electrical conductor , a second 1-turn coil body which is disposed in ...

Advanced Fe-5Cr-X Alloy

A tubular article can be formed from high temperature steam oxidation resistant and high temperature creep resistant alloy steel. The steel can include a chemical composition that include Fe, C, Si, Mn, Ni, Cr, Cu, Ti, Nb, Mo, and N, and optionally other elements. The steel alloy can include 0.06 to 0.15 wt % C, 0.1 to 0.5 wt % Si, 0.2 to 0.6 wt %, 0.05 to 0.4 wt % Ni, 4.5 to 6.0 wt % Cr, 1.0 to 2.0 wt % Cu, 0.04 to 0.08 wt % Ti, 0.01 to 0.06 wt % Nb, 0.45 to 1.2 wt % Mo, and 0.008 to 0.05 wt % N, up to 0.01 wt % of optional element Al, up to 0.01 wt % of optional element Zr, up to 3.0 wt % of optional element Co, up to 0.07 wt % of optional element V, up to 3.0 wt % of optional element W, up to 0.015 wt % of optional element P, up to 0.003 wt % of optional element S, up to 0.1 wt % of optional element Ca, up to 0.1 wt % of optional element Ta, up to 0.1 wt % of optional element Mg, up to 0.1 wt % of optional element Se, up to 0.1 wt % of optional element Te, up to 0.1 wt % of optional element B, up to 0.1 wt % of optional element Bi, and Fe. The steel can include copper precipitates and fine carbides, nitrides, or both. The steel can have a final microstructure comprising tempered martensite, tempered bainite, or a combination thereof. The steel can contain less than 2 vol % residual austenite. 2. The tubular article of claim 1 , wherein the steel contains less than 1 vol % residual austenite.3. The tubular article of claim 1 , wherein less than 4 wt % of the total Cr amount is stable in solid solution at room temperature.4. The tubular article of claim 1 , wherein the steel is comprising maximum 25 percent bainite.5. The tubular article of claim 1 , wherein wt % Ta+wt % Nb<0.1 wt %.6. The tubular article of claim 1 , wherein the copper precipitates have a grain size of less than 40 nm.7. The tubular article of claim 1 , wherein the fine carbides have a mean diameter of less than 200 nm.8. The tubular article of claim 7 , wherein the fine carbides have a size ...

Octg pipe system and method of manufacturing thereof

A pipe system for oil country tubular goods (OCTG) and a method of manufacturing the OCTG pipe system is disclosed. The pipe system includes at least one OCTG pipe having a pipe body, the pipe body having at least one connection end formed in unipartite and materially integral manner with the pipe body for coupling to a second OCTG pipe. The OCTG pipe is formed in seamless fashion from a hardenable steel alloy, and the connection end has a yield strength higher than the yield strength of the pipe body.

Process for manufacturing high-nitrogen stainless steel pipe with high strength, high ductility, and excellent corrosion and heat resistance

A process for manufacturing a high nitrogen stainless steel pipe material includes keeping an outside surface and/or an inside surface of an austenite stainless steel pipe material in contact with a substance that becomes a nitrogen (N) source, heating the steel pipe together with the nitrogen source substance at a temperature of 800° C. to 1100° C. in a range of temperatures not higher than the critical temperature for crystal grain enlargement of the steel pipe material to cause nitrogen to be absorbed into the surface of the pipe and diffused into the steel solid phase, and applying to the heat-treated pipe material annealing treatment in the range of temperatures in vacuum, inert gas including argon gas or an atmosphere of a gas with a reducing substance including H 2 gas added thereto, to result in a decrease of nitrogen concentration gradient.

APPARATUS AND METHOD FOR QUENCHING RODS AND TUBES

The present invention relates to a apparatus for statically quenching a product () coming from a rolling plant, comprising a seat for housing the product () so that, when the product () is housed there, its main development axis (A) coincides with the positioning axis (Z), a series of nozzles () arranged around the positioning axis (Z), along a curvilinear surface (), open at the bottom, and adjustable so as to dispense a flow which is tangential to the surface of the product (). The invention also relates to a process for static quenching of the product, implementable by such apparatus. 15-. (canceled)6. Apparatus for statically quenching rods and tubes equipped with a main development axis (A) and coming from a rolling plant , the apparatus comprising a seat for housing a rod or tube equipped with positioning axis (Z) , so that when the rod or tube is housed in the seat the main development axis (A) of the rod or tube coincides with the positioning axis (Z) , a series of first external nozzles for dispensing quenching agent arranged around the positioning axis (Z) , wherein the first external nozzles are arranged along a curvilinear surface , substantially equidistant from the positioning axis (Z) , the first external nozzles being adjustable so as deliver a flow of quenching agent tangential to the surface of the rod or tube , wherein longitudinally moving means and lifting means are comprised for positioning the rod or tube coming from the rolling plant so that the main development axis (A) of the rod or tube coincides with the positioning axis (Z) ,wherein the curvilinear surface has an absence of first external nozzles which defines an opening at the bottom so that the first external nozzles are arranged asymmetrically, that possible detached pieces due to possible cracks fall freely and that the lifting means, supporting the product and permitting the evacuation, pass through the opening at the bottom of the curvilinear surface.7. Apparatus for the static ...

HIGH-STRENGTH SEAMLESS STEEL PIPE FOR OIL COUNTRY TUBULAR GOODS AND METHOD OF PRODUCING THE SAME

Provided is a high-strength seamless steel pipe having the composition which contains, by mass %, 0.20 to 0.50% C, 0.05 to 0.40% Si, 0.3 to 0.9% Mn, 0.015% or less P, 0.005% or less S, 0.005 to 0.1% Al, 0.008% or less N, more than 0.6% and 1.7% or less Cr, more than 1.0% and 3.0% or less Mo, 0.01 to 0.30% V, 0.001% or more and less than 0.01% Nb, 0.0003 to 0.0030% B, and 0.0030% or less O (oxygen). The high-strength seamless steel pipe has the microstructure where a volume fraction of a tempered martensitic phase is 95% or more, and prior austenitic grains have a grain size number of 8.5 or more, and a segregation degree index Ps which is defined by a formula Ps=8.1 (X+X+X)+1.2Xis set to less than 65. 1. A high-strength seamless steel pipe for an oil country tubular goods having the composition which contains , by mass % , 0.20 to 0.50% C , 0.05 to 0.40% Si , 0.3 to 0.9% Mn , 0.015% or less P , 0.005% or less S , 0.005 to 0.1% Al , 0.008% or less N , more than 0.6% and 1.7% or less Cr , more than 1.0% and 3.0% or less Mo , 0.01 to 0.30% V , 0.001% or more and less than 0.01% Nb , 0.0003 to 0.0030% B , 0.0030% or less O (oxygen) , and Fe and unavoidable impurities as a balance , wherein{'sub': 'M', 'the steel pipe has the microstructure where a volume fraction of a tempered martensitic phase is 95% or more, and prior austenitic grains have a grain size number of 8.5 or more, and a segregation degree index Ps which is defined by a following formula (1) using Xwhich is a ratio between a segregated portion content obtained by performing an area analysis of respective elements by an electron probe micro analyzer (EPMA) in a region having the center thereof positioned at ¼ t (t: wall thickness) from an inner surface of the steel pipe and an average content is set to less than 65, and a yield strength YS is 862 MPa or more,'} {'br': None, 'i': Ps=', 'X', '+X', '+X', 'X, 'sub': Si', 'Mn', 'Mo', 'P, '8.1 ()+1.2\u2003\u2003(1)'}, 'wherein'}{'sub': 'M', 'where X: (segregated ...

MARTENSITIC STAINLESS STEEL SEAMLESS PIPE FOR OIL COUNTRY TUBULAR GOODS, AND METHOD FOR MANUFACTURING SAME

The invention is intended to provide a martensitic stainless steel seamless pipe for oil country tubular goods having high strength, and excellent sulfide stress corrosion cracking resistance. A method for manufacturing such a martensitic stainless steel seamless pipe is also provided. The martensitic stainless steel seamless pipe for oil country tubular goods has a yield stress of 758 MPa or more, and a composition that contains, in mass %, C: 0.0010 to 0.0094%, Si: 0.5% or less, Mn: 0.05 to 0.5%, P: 0.030% or less, S: 0.005% or less, Ni: 4.6 to 7.3%, Cr: 10.0 to 14.5%, Mo: 1.0 to 2.7%, Al: 0.1% or less, V: 0.2% or less, N: 0.1% or less, Ti: 0.01 to 0.50%, Cu: 0.01 to 1.0%, and Co: 0.01 to 1.0%, in which C, Mn, Cr, Cu, Ni, Mo, W, Nb, N, and Ti satisfy the predetermined relations, and the balance is Fe and incidental impurities. 1. A martensitic stainless steel seamless pipe for oil country tubular goods having a yield stress of 758 MPa or more , the martensitic stainless steel seamless pipe having a composition that comprises , in mass % , C: 0.0010 to 0.0094% , Si: 0.5% or less , Mn: 0.05 to 0.5% , P: 0.030% or less , S: 0.005% or less , Ni: 4.6 to 7.3% , Cr: 10.0 to 14.5% , Mo: 1.0 to 2.7% , Al: 0.1% or less , V: 0.2% or less , N: 0.1% or less , Ti: 0.01 to 0.50% , Cu: 0.01 to 1.0% , and Co: 0.01 to 1.0% , in which the values of the following formulae (1) and (2) satisfy the formulae (3) below , and the balance is Fe and incidental impurities:{'br': None, '−109.37C+7.307Mn+6.399Cr+6.329Cu+11.343Ni−13.529Mo+1.276W+2.925Nb+196.775N−2.621Ti−120.307,\u2003\u2003Formula (1)'}{'br': None, '−1.324C+0,0533Mn+0.0268Cr+0.0893Cu+0.00526Ni+0.0222Mo−0.0132W−0.473N−0.5Ti−0.514,\u2003\u2003Formula (2)'} [{'br': None, '−35.0≤value of formula (1)≤45, and'}, {'br': None, '−0.40≤value of formula (2)≤0.070.\u2003\u2003Formulae (3)'}], 'wherein C, Mn, Cr, Cu, Ni, Mo, W, Nb, N, and Ti represent the content of each element in mass %, and the content is 0 (zero) for elements that are ...

METHOD FOR MANUFACTURING BAINITE HIGH-STRENGTH SEAMLESS STEEL TUBE, AND BAINITE HIGH-STRENGTH SEAMLESS STEEL TUBE

A method for manufacturing a bainite high-strength seamless steel tube, comprising the following steps: smelting, manufacturing a billet, heating, perforating, rolling, stretch reducing or sizing to obtain tube, and cooling. In the cooling step, the quenching starting temperature is controlled to be at least 20° C. higher than the Ar3 temperature of the steel grade; the finish cooling temperature is controlled to be within a range between T1 and T2, where T1=519−423C−30.4Mn, T2=780−270C−90Mn, and the units of the T1 and the T2 are ° C.; in the formulas, C and Mn respectively represent the mass percents of element C and element Mn of the steel grade, the content of the element C is 0.06-0.2%, and the content of the element Mn is 1-2.5%; the cooling rate is controlled to be 15-80° C./s; and the finished product of the bainite high-strength seamless steel tube is directly obtained after the cooling step. The manufacturing of a bainite high-strength seamless steel tube using the method requires neither the addition of precious alloying elements nor the subsequent heat treatment. Therefore the production costs are low. 1. A method for manufacturing a bainite high-strength seamless steel tube , comprising the following steps: smelting , manufacturing a billet , heating , piercing , rolling , stretch reducing or sizing to obtain tube , and cooling; wherein the cooling step comprisescontrolling the quenching starting temperature to be less than or equal to the Ar3 temperature of the steel grade +20° C.; wherein T1=519−423C−30.4Mn, T2=780−270C−90Mn, and units of T1 and T2 are ° C.; in the formulas, C and Mn respectively represent the mass percents of element C and element Mn of the steel grade,', 'and wherein the content of the element C is 0.06-0.2%, and the content of the element Mn is 1-2.5%; and, 'controlling the finish cooling temperature to be within a range between T1 and T2,'}controlling the cooling rate to be 15-80° C./s;wherein the finished product of the bainite ...

WELLBORE TUBULAR AIR QUENCHING

A system for air quenching a heat treated element comprises a tubular component, an internal air quench device moveably disposed within the interior of the tubular component, and an external air quench device moveably disposed about the tubular component. The internal air quench device comprises a nozzle configured to induce an airflow within the tubular component. The external air quenching device can comprise an annular ring disposed about the tubular component that is configured to generate a cone of air about the tubular component. 1. A system for air quenching a heat treated element , the system comprising:a tubular component;an internal air quench device moveably disposed within the interior of the tubular component, wherein the internal air quench device comprises a nozzle configured to induce an airflow within the tubular component; andan external air quench device disposed about the tubular component and moveable relative to the tubular component.2. The system of claim 1 , further comprising an induction coil disposed about the tubular component claim 1 , wherein the induction coil is configured to heat the tubular and create a heat affected zone.3. The system of claim 2 , wherein the heat affected zone includes a weld line between two tubulars.4. The system of claim 1 , wherein the tubular component comprises a drill pipe claim 1 , a drill collar claim 1 , a production pipe claim 1 , a tool joint claim 1 , or a downhole tool housing.5. The system of claim 1 , further comprising a compressed air source claim 1 , wherein the nozzle and the external air quench device are in fluid communication with the compressed air source.6. The system of claim 1 , wherein the tubular comprises a heat affected zone claim 1 , wherein the internal air quench device is disposed a first longitudinal distance away from a centerline of the heat affected zone claim 1 , wherein the external air quench device is disposed a second longitudinal distance away from the centerline of the ...

HEAT TREATED STEEL PRODUCT HAVING HIGH STRENGTH AND EXCELLENT CHEMICAL CONVERSION COATING ABILITY AND METHOD OF PRODUCTION OF SAME

A steel product bent by heating to 600° C. or more, specifically a heat treated steel product having high strength and excellent chemical conversion coating ability which has scale with FeO content of 90% or more, having a thickness of 1 μm or less on the surface. 1. Heat treated steel product comprising a scale with FeO content of 90% or more , having a thickness of 1 μm or less on the surface.2. The heat treated steel product according to claim 1 , wherein the steel has a structure consisting of martensite claim 1 , or martensite and tempered martensite.3. The heat treated steel product according to claim 1 , wherein the steel product is a hollow member having a closed horizontal cross-sectional shape.4. The heat treated steel product according to claim 1 , wherein a maximum value and a minimum value of the thickness of the scale are within ±10% of an average value of the thickness.5. A method of producing a heat treated steel product using a working apparatus having a gas chamber claim 1 , a heating device claim 1 , and a cooling device from an upstream side claim 1 , said method of producing the heat treated steel product comprisingintroducing an inert gas into a gas chamber and filling the inert gas into a space including the heating device and the cooling device whilemaking the working apparatus move relative to a steel material so that the steel material is locally heated by the heating device then the steel material is cooled by the cooling device, whereina time period during which the steel material dwells in a 600° C. or more temperature region is less than 1 second andbetween the heating and cooling, a bending operation is performed at a portion of the steel material greatly dropping in deformation resistance due to heating.6. The method of producing a heat treated steel product according to claim 5 , wherein in the step of cooling claim 5 , a time period during which the steel material dwells in a 600° C. to 300° C. temperature region is within 3 seconds ...