公开(公告)号：US20220235442A1

公开(公告)日：2022-07-28

申请号：US17442744

申请日：2020-03-26

申请人： JFE Steel Corporation

发明人： Yoshihiko Ono ,  Yasushi Kitani ,  Hiroyuki Akimoto ,  Yoichiro Matsui

IPC分类号： C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/34 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/58 ,  C22C38/60 ,  C21D1/25 ,  C21D1/76 ,  C21D8/02 ,  C21D8/04 ,  C21D9/48

摘要： The steel sheet has a steel microstructure containing ferrite: 6% to 90% by area, a microstructure composed of one or more of upper bainite, fresh martensite, tempered martensite, lower bainite, and retained γ: 10% to 94% by area in total, and retained γ: 3% to 20% by volume, a ratio (SUB/S2nd)×100(%) of an area ratio SUB of an upper bainite with a width in the range of 0.8 to 7 μm, a length in the range of 2 to 15 μm, and an aspect ratio of 2.2 or more in contact with retained γUB with a grain width in the range of 0.17 to 0.80 μm and an aspect ratio in the range of 4 to 25 to an area ratio S2nd of the microstructure composed of one or more of upper bainite, fresh martensite, tempered martensite, lower bainite, and retained γ ranges from 2.0% to 15%.

公开(公告)号：US12043876B2

公开(公告)日：2024-07-23

申请号：US17285375

申请日：2019-10-16

申请人： JFE STEEL CORPORATION

发明人： Yoshihiko Ono ,  Junya Tobata ,  Hiroyuki Akimoto ,  Yoichiro Matsui ,  Shinjiro Kaneko

IPC分类号： C21D1/22 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58

CPC分类号： C21D9/46 ,  C21D1/22 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008

摘要： A steel sheet having a specified chemical composition and a method for producing the steel sheet. The steel sheet has a microstructure comprising ferrite: 5% or less, and at least one of upper bainite, fresh martensite, tempered martensite, lower bainite, and retained γ: 95% to 100%, and retained γ: 5% to 20%. Retained γUB has a specified area percentage SγUB, retained γLB has a specified distribution number NγLB, and at least one of (i) fresh martensite has a specified equivalent circular grain diameter and aspect ratio and (ii) retained γ grains has a specified equivalent circular grain diameter and aspect ratio.

公开(公告)号：US12123069B2

公开(公告)日：2024-10-22

申请号：US17286148

申请日：2019-10-16

申请人： JFE STEEL CORPORATION

发明人： Yoshihiko Ono ,  Junya Tobata ,  Hiroyuki Akimoto ,  Yoichiro Matsui ,  Shinjiro Kaneko

IPC分类号： C21D9/46 ,  C21D1/20 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60

CPC分类号： C21D9/46 ,  C21D1/20 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/42 ,  C22C38/44 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008

摘要： A steel sheet having a specified chemical composition and a method for producing the steel sheet. The steel sheet has a microstructure comprising ferrite: 5% or less, and at least one of upper bainite, fresh martensite, tempered martensite, lower bainite, and retained γ: 95% to 100% by area percentage, and retained γ: 4% to 15% by volume percentage. Retained γUB has a specified area percentage SγUB, retained γLB has a specified distribution number NγLB, and at least one of (i) fresh martensite has a specified equivalent circular grain diameter and aspect ratio and (ii) retained γ grains has a specified equivalent circular grain diameter and aspect ratio.

公开(公告)号：US20200157647A1

公开(公告)日：2020-05-21

申请号：US16604398

申请日：2018-04-13

申请人： JFE Steel Corporation

发明人： Yoshihiko Ono ,  Junya Tobata ,  Hiroyuki Akimoto

IPC分类号： C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/60 ,  C22C38/14 ,  C22C38/12 ,  C22C38/16 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

摘要： A steel sheet and a manufacturing method therefor are provided.A steel sheet has a component composition and contains 6 to 80% of ferrite and 20 to 94% of a microstructure composed of one or two or more of upper bainite, fresh martensite, tempered martensite, lower bainite, and retained γ, and contains 7 to 20% of retained γ, where: an area ratio (SγUB) of retained γ having a particle width of 0.18 to 0.60 μm, a particle length of 1.7 to 7.0 μm, and an aspect ratio of 5 to 15 is 0.2 to 5%; and a total area ratio (SγBlock) of fresh martensite having an equivalent circle diameter of 1.5 to 15 μm and an aspect ratio of 3 or less and/or retained γ particles having an equivalent circle diameter of 1.5 to 15 μm and an aspect ratio of 3 or less is 3% or less (including 0%).