公开(公告)号：US20190316236A1

公开(公告)日：2019-10-17

申请号：US16470343

申请日：2017-12-04

Applicant: JFE Steel Corporation

Inventor： Tetsuyuki Nakamura ,  Shin Ishikawa ,  Reiko Sugihara

IPC: C22C38/12 ,  C22C38/52 ,  C22C38/54 ,  C22C38/00 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/42 ,  C22C38/44

Abstract: Provided is a ferritic stainless steel sheet. The steel sheet has a chemical composition containing, by mass %, C: 0.010% or less, Si: 1.0% or less, Mn: 1.0% or less, P: 0.040% or less, S: 0.030% or less, Cr: 17.0% or more and 18.5% or less, N: 0.015% or less, Nb: 0.40% or more and 0.80% or less, Ti: 0.10% or more and 0.40% or less, Al: 0.20% or less, Ni: 0.05% or more and 0.40% or less, Co: 0.01% or more and 0.30% or less, Mo: 0.02% or more and 0.30% or less, Cu: 0.02% or more and 0.40% or less, and the balance being Fe and inevitable impurities, in which expression (1) below is satisfied. C %+N %: 0.018% or less  (1) In expression (1), C % and N % respectively denote the contents (mass %) of C and N.

公开(公告)号：US20180002778A1

公开(公告)日：2018-01-04

申请号：US15542272

申请日：2015-08-28

Applicant: JFE STEEL CORPORATION

Inventor： Nobusuke Kariya ,  Yoshihiko Ono ,  Yoshimasa Funakawa ,  Kazuma Mori ,  Reiko Sugihara ,  Kenji Kawamura

IPC: C21D9/46 ,  B21B1/22 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/16 ,  C22C38/08 ,  C22C38/02 ,  C22C38/00 ,  C22C38/38 ,  B21B3/02 ,  C21D6/00 ,  C21D8/02 ,  C23G1/00

Abstract: Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 25% or less of a ferrite phase, 75% or more of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 5% to 20%, and a tensile strength is 1180 MPa or more.

公开(公告)号：US09631250B2

公开(公告)日：2017-04-25

申请号：US14383008

申请日：2013-02-28

Applicant: JFE STEEL CORPORATION

Inventor： Hidetaka Kawabe ,  Takeshi Yokota ,  Reiko Sugihara ,  Shigeyuki Aizawa ,  Kazuki Nakazato

IPC: C21D8/02 ,  C22C38/14 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C21D8/04 ,  C21D9/48 ,  C21D1/25 ,  C21D1/26

CPC classification number: C21D8/0263 ,  C21D1/25 ,  C21D1/26 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0278 ,  C21D8/0436 ,  C21D8/0473 ,  C21D9/48 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14

Abstract: A steel sheet has a microstructure including ferrite phase: 40% to 60%, bainite phase: 10% to 30%, tempered martensite phase: 20% to 40%, and retained austenite phase: 5% to 20% by volume fraction, and satisfying a condition that a ratio of tempered martensite phase having major axis length ≦5 μm to a total volume fraction of the tempered martensite phase is 80% to 100%.

公开(公告)号：US20150034219A1

公开(公告)日：2015-02-05

申请号：US14383008

申请日：2013-02-28

Applicant: JFE STEEL CORPORATION

Inventor： Hidetaka Kawabe ,  Takeshi Yokota ,  Reiko Sugihara ,  Shigeyuki Aizawa ,  Kazuki Nakazato

IPC: C21D8/02 ,  C22C38/14 ,  C22C38/00 ,  C22C38/04 ,  C22C38/02 ,  C21D1/26 ,  C22C38/06

CPC classification number: C21D8/0263 ,  C21D1/25 ,  C21D1/26 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0278 ,  C21D8/0436 ,  C21D8/0473 ,  C21D9/48 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14

Abstract: A steel sheet has a microstructure including ferrite phase: 40% to 60%, bainite phase: 10% to 30%, tempered martensite phase: 20% to 40%, and retained austenite phase: 5% to 20% by volume fraction, and satisfying a condition that a ratio of tempered martensite phase having major axis length ≦5 μm to a total volume fraction of the tempered martensite phase is 80% to 100%.

Abstract translation: 钢板具有包含铁素体相的组织：40％〜60％，贝氏体相：10％〜30％，回火马氏体相：20％〜40％，残留奥氏体相：5体积％〜20体积％，以及 满足以下条件：具有长径比长度为nlE的回火马氏体相与回火马氏体相的总体积分数相比为80％至100％的条件。

公开(公告)号：US20210277494A1

公开(公告)日：2021-09-09

申请号：US16497507

申请日：2017-05-25

Applicant: JFE Steel Corporation

Inventor： Tomohiro Ishii ,  Mitsuyuki Fujisawa ,  Reiko Sugihara ,  Chikara Kami

IPC: C21D9/46 ,  C22C38/54 ,  C22C38/52 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00

Abstract: Provided is a ferritic stainless steel in which cracking is unlikely to be caused in the vicinity of a weld zone by the stress due to expansion, contraction, and deformation due to the thermal effect of welding in the case of performing welding after deep drawing and which is excellent in corrosion resistance in the vicinity of the weld zone.
The ferritic stainless steel has a composition containing C: 0.001% to 0.020%, Si: 0.01% to 0.30%, Mn: 0.01% to 0.50%, P: 0.04% or less, S: 0.01% or less, Cr: 18.0% to 24.0%, Ni: 0.01% to 0.40%, Mo: 0.30% to 3.0%, Al: 0.01% to 0.15%, Ti: 0.01% to 0.50%, Nb: 0.01% to 0.50%, V: 0.01% to 0.50%, Co: 0.01% to 6.00%, B: 0.0002% to 0.0050%, and N: 0.001% to 0.020% on a mass basis, the remainder being Fe and inevitable impurities. The composition satisfies 0.30%≤Ti+Nb+V≤0.60%.

公开(公告)号：US10760142B2

公开(公告)日：2020-09-01

申请号：US15542203

申请日：2015-08-28

Applicant: JFE STEEL CORPORATION

Inventor： Nobusuke Kariya ,  Yoshihiko Ono ,  Yoshimasa Funakawa ,  Kazuma Mori ,  Reiko Sugihara ,  Kenji Kawamura

IPC: C21D9/46 ,  C22C38/14 ,  C22C38/60 ,  C22C38/00 ,  C21D6/00 ,  C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/16 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38

Abstract: Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 30% or more of a ferrite phase, 40% to 65% of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 40% to 55% and the total area ratio of a bainite phase having a grain diameter of more than 5 μm and/or a martensite phase having a grain diameter of more than 5 μm is 20% or less, and a tensile strength is 980 MPa or more.

公开(公告)号：US20190177825A1

公开(公告)日：2019-06-13

申请号：US16325575

申请日：2017-08-25

Applicant: JFE Steel Corporation

Inventor： Takayoshi Yano ,  Kunio Fukuda ,  Shin Ishikawa ,  Katsuhisa Yamauchi ,  Reiko Sugihara ,  Hideya Matsumoto

IPC: C22C38/60 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/00 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/52 ,  C22C38/50 ,  C22C38/54

Abstract: Provided is a ferritic stainless steel that has good corrosion resistance and which exhibits good brazeability when subjected to high-temperature brazing with a Ni-containing brazing filler metal.The ferritic stainless steel has a composition containing, in mass %, C: 0.003 to 0.020%, Si: 0.05 to 0.60%, Mn: 0.05 to 0.50%, P: 0.04% or less, S: 0.02% or less, Cr: 17.0 to 24.0%, Ni: 0.20 to 0.80%, Cu: 0.01 to 0.80%, Mo: 0.01 to 2.50%, Al: 0.001 to 0.015%, Nb: 0.25 to 0.60%, and N: 0.020% or less, with the balance being Fe and incidental impurities, the composition satisfying formula (1) below and formula (2) below, Cu+Mo≥0.30  (1) 4Ni−(Si+Mn)≥0  (2) (wherein Cu and Mo in formula (1) and Ni, Si, and Mn in formula (2) each represent the content (mass %) of the corresponding element).

公开(公告)号：US10072316B2

公开(公告)日：2018-09-11

申请号：US14436685

申请日：2013-10-16

Applicant: JFE STEEL CORPORATION

Inventor： Hidetaka Kawabe ,  Takeshi Yokota ,  Reiko Sugihara ,  Daigo Itoh ,  Kazunori Tahara

IPC: C21D9/46 ,  C21D8/02 ,  C22C38/14 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C21D6/00

CPC classification number: C21D9/46 ,  C21D6/005 ,  C21D6/008 ,  C21D8/02 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0263 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14

Abstract: A cold-rolled steel sheet having a steel composition comprising, by mass %, 0.12% to 0.22% C, 0.8% to 1.8% Si, 1.8% to 2.8% Mn, 0.020% or less P, 0.0040% or less S, 0.005% to 0.08% Al, 0.008% or less N, 0.001% to 0.040% Ti, 0.0001% to 0.0020% B, 0.0001% to 0.0020% Ca, and Fe and incidental impurities. The steel sheet includes a microstructure in which ferrite and bainite phases are 50% to 70% of the total area, the average grain size of the ferrite and bainite phase is 1 to 3 μm, a tempered martensite phase is 25% to 45% of the total area, the average grain size of the tempered martensite phase is 1 to 3 μm, and a retained austenite phase is 2% to 10% of the total area.

公开(公告)号：US10697039B2

公开(公告)日：2020-06-30

申请号：US15542272

申请日：2015-08-28

Applicant: JFE STEEL CORPORATION

Inventor： Nobusuke Kariya ,  Yoshihiko Ono ,  Yoshimasa Funakawa ,  Kazuma Mori ,  Reiko Sugihara ,  Kenji Kawamura

IPC: C21D9/46 ,  C22C38/06 ,  C22C38/40 ,  C22C38/12 ,  C22C38/04 ,  C22C38/50 ,  C22C38/00 ,  C22C38/18 ,  B21B3/00 ,  C22C38/58 ,  C22C38/14 ,  C22C38/60 ,  B21B1/22 ,  B21B3/02 ,  C21D6/00 ,  C21D8/02 ,  C22C38/02 ,  C22C38/08 ,  C22C38/16 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C23G1/00

Abstract: Provided are a high-strength steel sheet and a method for manufacturing the steel sheet. The high-strength steel sheet has a specified chemical composition with the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 25% or less of a ferrite phase, 75% or more of a bainite phase and/or a martensite phase, and 5% or less of cementite, in which, in a surface layer that is a region within 50 μm from the surface in the thickness direction, the area ratio of a ferrite phase is 5% to 20%, and a tensile strength is 1180 MPa or more.

公开(公告)号：US20190177824A1

公开(公告)日：2019-06-13

申请号：US16325577

申请日：2017-08-25

Applicant: JFE Steel Corporation

Inventor： Manami Ichikawa ,  Tetsuyuki Nakamura ,  Kunio Fukuda ,  Shin Ishikawa ,  Reiko Sugihara

IPC: C22C38/54 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/00 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/34 ,  C22C38/52 ,  C22C38/50

Abstract: Provided is ferritic stainless steel having excellent brazeability and excellent corrosion resistance to condensed water in an environment in which the steel is used for an exhaust heat recovery device or an EGR cooler.A ferritic stainless steel has a chemical composition containing, by mass %, C: 0.025% or less, Si: 0.40% to 2.0%, Mn: 0.05% to 1.5%, P: 0.05% or less, S: 0.01% or less, Cr: 16.0% to 30.0%, Mo: 0.60% to 3.0%, Ni: 0.10% to 2.5%, Nb: 0.20% to 0.80%, Al: 0.001% to 0.15%, N: 0.025% or less, and the balance being Fe and inevitable impurities, in which relational expressions (1) and (2) below are satisfied. C+N≤0.030%  (1), 2Si+Ni≥1.0%  (2), (in relational expressions (1) and (2), C, N, Si, and Ni each denote the contents (mass %) of the corresponding elements).