公开(公告)号：EP3321387A4

公开(公告)日：2018-05-16

申请号：EP16821038

申请日：2016-07-05

Applicant: JFE STEEL CORP

Inventor： KIZU TARO ,  TOYODA SHUNSUKE ,  KIDO AKIMASA ,  TADANI TETSUSHI

IPC: C22C38/00 ,  B21B1/22 ,  B21B3/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/24 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58 ,  C22C38/60

CPC classification number: B21B1/22 ,  B21B3/00 ,  C21D8/0226 ,  C21D8/0263 ,  C21D9/46 ,  C21D2211/004 ,  C22C38/00 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/24 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58 ,  C22C38/60

Abstract: This disclosure provides a predetermined composition, where a conversion value C* of total carbon contents in Ti, Nb and V precipitates whose grain sizes are less than 20 nm is 0.010 mass% to 0.100 mass%, Fe content in Fe precipitates is 0.03 mass% to 0.50 mass%, and an average grain size of ferrite grains whose grain sizes are top 5 % large in ferrite grain size distribution of rolling direction cross section is (4000/TS) 2 µm or less, the TS indicating tensile strength in unit of MPa.

公开(公告)号：EP3266897A4

公开(公告)日：2018-03-28

申请号：EP16761275

申请日：2016-03-01

Applicant: JFE STEEL CORP

Inventor： KIZU TARO ,  TOYODA SHUNSUKE ,  KIDO AKIMASA ,  TADANI TETSUSHI

IPC: C22C38/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58 ,  C22C38/60

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58 ,  C22C38/60 ,  Y02P10/212

Abstract: A high strength steel sheet having high strength such as a tensile strength of 780 MPa or more and having excellent blanking workability and stretch flangeability and a manufacturing method therefor are provided. A high strength steel sheet comprises: a chemical composition containing, in mass%, C: 0.05% to 0.30%, Si: 0.6% to 2.0%, Mn: 1.3% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 2.0% or less, N: 0.010% or less, and one or more of Ti, Nb, and V: 0.01% to 1.0% each, with a balance being Fe and incidental impurities; a ferrite microstructure of 50% or more in area ratio; an amount of precipitated Fe of 0.04 mass% or more; and a precipitate with a particle size of less than 20 nm, wherein C* defined by the following Expression (1) and C* p defined by the following Expression (2) meet conditions of the following Expressions (3) to (5): C * = Ti / 48 + Nb / 93 + V / 51 + Mo / 96 + Ta / 181 + W / 184 × 12 C * p = Ti p / 48 + Nb p / 93 + V p / 51 + Mo p / 96 + Ta p / 181 + W p / 184 × 12 C * ‰¥ 0.035 ˆ’ 0.015 ‰¤ C ˆ’ C * ‰¤ 0.03 C * p / C * ‰¥ 0.3

公开(公告)号：EP2927339A4

公开(公告)日：2015-12-16

申请号：EP14743980

申请日：2014-01-23

Applicant: JFE STEEL CORP

Inventor： GOTO SOTA ,  TOYODA SHUNSUKE ,  OKABE TAKATOSHI ,  OKAZAKI YUKIHIKO

IPC: C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0263 ,  C21D2211/004 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50

公开(公告)号：EP2837708A4

公开(公告)日：2015-08-12

申请号：EP13775345

申请日：2013-04-11

Applicant: JFE STEEL CORP

Inventor： TOYODA SHUNSUKE ,  GOTO SOTA ,  OKABE TAKATOSHI ,  INOUE TOMOHIRO ,  EGI MOTOHARU ,  YONEMOTO ATSUSHI

IPC: C22C38/04 ,  B21B3/00 ,  B21C37/08 ,  C21D1/00 ,  C21D8/02 ,  C21D8/10 ,  C21D9/08 ,  C21D9/50 ,  C22C38/14 ,  C22C38/58

CPC classification number: F16L9/02 ,  B21B3/00 ,  B21B27/06 ,  B21B27/08 ,  B21C37/08 ,  B23K11/0073 ,  B23K11/0873 ,  B32B1/08 ,  C21D1/00 ,  C21D8/02 ,  C21D8/0226 ,  C21D8/0263 ,  C21D8/105 ,  C21D9/08 ,  C21D9/085 ,  C21D9/50 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/58 ,  F16L9/17 ,  Y10T428/12958 ,  Y10T428/12965 ,  Y10T428/12972 ,  Y10T428/12979 ,  Y10T428/13

Abstract: There is provided a high-strength thick-walled electric resistance welded steel pipe having excellent low-temperature toughness and excellent HIC resistance and having a yield strength of 400 MPa or more. Steel is heated to and held at a temperature in the range of 1200°C to 1280°C. 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. The steel is hot-rolled at a rolling reduction of 20% or more in an unrecrystallization temperature range. After the completion of the hot-rolling, the steel is cooled to a finish cooling temperature of 630°C or less at a cooling rate in the range of 7°C/s to 49°C/s and is coiled at 400°C or more and less than 600°C to form a hot-rolled steel strip. The hot-rolled steel strip is subjected to roll-forming and electric resistance welding to produce an electric resistance welded steel pipe. The welded portion of the electric resistance welded steel pipe is then subjected to a heat treatment in which the welded portion is heated to a temperature in the range of 800°C to 1150°C over the total wall thickness and is then cooled to 630°C or less at an average cooling rate in the range of 7°C/s to 49°C/s. The base steel portion and the electric resistance welded portion of the resulting high-strength thick-walled electric resistance welded steel pipe have excellent low-temperature toughness and excellent HIC resistance.

公开(公告)号：EP3279353A4

公开(公告)日：2018-02-07

申请号：EP16771783

申请日：2016-03-30

Applicant: JFE STEEL CORP

Inventor： TANAKA TAKAAKI ,  KIZU TARO ,  TOYODA SHUNSUKE

IPC: C22C38/00 ,  C21D6/00 ,  C21D6/02 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/22 ,  C22C38/28 ,  C22C38/38 ,  C22C38/60

CPC classification number: C21D9/46 ,  C21D6/005 ,  C21D6/008 ,  C21D6/02 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0263 ,  C21D8/0273 ,  C21D2211/002 ,  C21D2211/004 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/22 ,  C22C38/28 ,  C22C38/38 ,  C22C38/60

Abstract: A hot rolled steel sheet comprises: a predetermined chemical composition; a microstructure in which a total area ratio of a tempered bainite phase and a tempered martensite phase is 70% or more, a total area ratio of a coarse pearlite phase, a martensite phase, and a retained austenite phase is 10% or less, the tempered bainite phase and the tempered martensite phase have laths with an average width of 1.0 µm or less as a substructure, a proportion of Fe-based carbides with an aspect ratio of 5 or less in Fe-based carbides precipitated inside and at boundaries of the laths is 80% or more, and MC-type carbides with an average particle size of 20 nm or less are dispersed and precipitated inside and at the boundaries of the laths; and an average dislocation density of 1.0 × 10 14 m -2 or more and 5.0 × 10 15 m -2 or less.

公开(公告)号：EP3020840A4

公开(公告)日：2016-08-03

申请号：EP14822859

申请日：2014-07-08

Applicant: JFE STEEL CORP

Inventor： GOTO SOTA ,  TOYODA SHUNSUKE ,  OKABE TAKATOSHI

IPC: C22C38/00 ,  B21C37/08 ,  C21D8/02 ,  C21D9/08 ,  C21D9/50 ,  C22C38/12 ,  C22C38/58

CPC classification number: C21D9/085 ,  B23K11/0873 ,  C21D1/42 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/105 ,  C21D9/08 ,  C21D9/50 ,  C21D9/505 ,  C21D2211/002 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/38 ,  C22C38/58 ,  Y02P10/253

Abstract: Provided is a heavy wall electric resistance welded steel pipe for a line pipe having a high strength of X52 grade or more specified by the API and a high toughness. 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, an electric resistance weld zone having 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 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 by performing a heat treatment on an electric resistance weld zone including performing induction heating such that an electric resistance weld zone has a minimum temperature of 830°C or higher and a maximum temperature of 1150°C or lower and performing a cooling treatment to a cooling stop temperature of 550°C or lower at an average cooling rate of 10°C/s or more and 70°C/s or less in every portion in the wall thickness direction. With this method, the heavy wall electric resistance welded steel pipe has high toughness, and 0.80 mm or more in terms of critical opening displacement ´ at a testing temperature of -25°C in a CTOD test even in the electric resistance weld zone.

Abstract translation: 提供了一种用于具有X52级或由API和高韧性多个指定的高强度的管线管厚壁电阻焊钢管。 通过使用作为原料的，具有化学组成包含一个厚的热轧钢板中，以质量％计，C：0.02％以上且0.10％以下，Si：0.05％以上且0.30％至或以下，Mn ：0.80％以上且2：00％或以下，及Nb：0.010％以上且0.100％以下，并满足条件做了碳当量Ceq为0.25％以上且0.50％以下，微结构包括贝氏体铁素体相 和/或贝氏体相，在屈服强度和-45℃或更低的在上具有微结构包含贝氏体电阻焊接区断裂转变临界温度vTrs的方面具有高韧性方面具有高强度的52个95ksi以上 铁素体相和/或贝氏体相和满足条件并最粗晶粒部分的平均晶粒尺寸为最好的晶粒部分的平均晶粒尺寸的比值在每个部分2.0或更小的壁厚 方向是通过在电resistan上进行热处理获得 切·韦尔德区包括执行感应加热搜索做了电阻焊接区具有830℃或更高的最低温度和1150℃或更低的最高温度和550℃以下的冷却停止温度进行冷却处理 在以10℃​​/ s以上且在壁厚方向各部分的70℃/ s以下的平均冷却速度。 用这种方法，所述重壁电阻焊钢管具有高韧性，并且在在CTOD试验，即使在电阻焊接区的-25℃的试验温度极限开口位移量”的术语0.80毫米以上。

公开(公告)号：EP1693476A4

公开(公告)日：2009-07-22

申请号：EP04807135

申请日：2004-12-09

Applicant: JFE STEEL CORP ,  TOYOTA MOTOR CO LTD

Inventor： TOYODA SHUNSUKE ,  SAKATA KEI ,  SATO AKIO ,  KANEKO KOUICHI ,  KAWAGUCHI HIROSHI

IPC: C21D9/46 ,  C22C38/00 ,  C21D8/02 ,  C21D8/10 ,  C22C38/58

CPC classification number: C22C38/02 ,  C21D8/0226 ,  C21D8/10 ,  C22C38/001 ,  C22C38/002 ,  C22C38/04 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38

Abstract: A method for producing a steel product which comprises providing a steel slab having a chemical composition satisfying C: 0.18 to 0.29 %, Si: 0.06 to 0.45 %, Mn: 0.91 to 1.85 %, P: 0.019 % or less, S: 0.0029% or less, sol.Al: 0.015 to 0.075%, N: 0.0049 % or less, O: 0.0049 % or less, B: 0.0001 to 0.0029 %, Nb: 0.001 to 0.019 %, Ti: 0.001 to 0.029 %, Cr: 0.001 to 0.195 %, Mo: 0.001 to 0.195 %, and 0.4 or more and less than 0.58 of Ceq, and satisfying that the sum (χ) of hardenability multiples according to Grossmann being aware of B is 1.2 or more and less than 1.7, heating the steel slab to 1160 to 1320˚C, subjecting the resultant slab to a hot finish rolling having an ending temperature for the finish rolling of 750 to 980˚C, annealing the rolled product for a period of 2s or more before winding, and then winding the product up at a temperature of 560 to 740˚C, to thereby produce a hot-rolled steel belt which has a structure having an average grain diameter (df) corresponding to a ferrite circle of 1.1 μm or more and less than 12 μm and a ferrite volume percentage (Vf) of 30 to 98 %. A steel pipe is produced by a method comprising using the above hot-rolled steel belt as a material and subjecting it to an electric welding wherein a reduction ratio for width is 8 % or less. A steel product produced by the above method is excellent in formability, fatigue strength after hardening, toughness at a low temperature, characteristics of resistance to delayed break and corrosion fatigue strength.

公开(公告)号：EP2927338A4

公开(公告)日：2015-12-16

申请号：EP14742727

申请日：2014-01-23

Applicant: JFE STEEL CORP

Inventor： GOTO SOTA ,  TOYODA SHUNSUKE ,  OKABE TAKATOSHI ,  OKAZAKI YUKIHIKO

IPC: C21D9/50 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50

CPC classification number: C21D9/46 ,  C21D8/02 ,  C21D8/0205 ,  C21D8/0226 ,  C21D9/50 ,  C21D2211/002 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/20 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50

公开(公告)号：EP2050833A4

公开(公告)日：2015-04-22

申请号：EP07767459

申请日：2007-06-19

Applicant: JFE STEEL CORP

Inventor： TOYODA SHUNSUKE ,  ARATANI MASATOSHI ,  KAWABATA YOSHIKAZU ,  HASHIMOTO YUJI ,  SUZUKI KOJI ,  SAKATA KEI ,  GUNJI MAKIO ,  SATO AKIO ,  SAWAKI TETSURO

IPC: C22C38/00 ,  B21C37/08 ,  C21D8/02 ,  C21D8/10 ,  C22C38/14 ,  C22C38/58

CPC classification number: B21C37/08 ,  C21D1/26 ,  C21D8/02 ,  C21D8/0226 ,  C21D8/0263 ,  C21D9/08 ,  C21D2211/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/12 ,  C22C38/14

公开(公告)号：EP2415539A4

公开(公告)日：2012-08-22

申请号：EP10758933

申请日：2010-03-31

Applicant: JFE STEEL CORP

Inventor： HASHIMOTO YUJI ,  TOYODA SHUNSUKE ,  NAKAGAWA KINYA ,  SUZUKI KOJI ,  KAWABATA YOSHIKAZU ,  SONOBE OSAMU ,  SATO AKIO

IPC: B21D53/88 ,  B21D11/02 ,  B21D17/02 ,  B60G9/04

CPC classification number: B21D53/88 ,  B21D9/15 ,  B21D11/02 ,  B21D17/02 ,  B21D22/025 ,  B60G21/051 ,  B60G2206/30 ,  B60G2206/80 ,  Y10T29/49622