- 专利标题: High-strength steel sheet excellent in workability and cold brittleness resistance, and manufacturing method thereof
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申请号: US13489005申请日: 2012-06-05
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公开(公告)号: US09745639B2公开(公告)日: 2017-08-29
- 发明人: Sae Mizuta , Yuichi Futamura , Yukihiro Utsumi
- 申请人: Sae Mizuta , Yuichi Futamura , Yukihiro Utsumi
- 申请人地址: JP Kobe-shi
- 专利权人: Kobe Steel, Ltd.
- 当前专利权人: Kobe Steel, Ltd.
- 当前专利权人地址: JP Kobe-shi
- 代理机构: Oblon, McClelland, Maier & Neustadt, L.L.P.
- 优先权: JP2011-130835 20110613
- 主分类号: C22C38/04
- IPC分类号: C22C38/04 ; C22C38/02 ; C21D1/20 ; C21D9/46 ; C22C38/00 ; C22C38/06 ; C22C38/08 ; C22C38/12 ; C22C38/14 ; C22C38/16 ; C22C38/18 ; C21D8/04
摘要:
The invention relates to a steel sheet having a tensile strength of 1180 MPa or more, which excels in workability and cold brittleness resistance. The high-strength steel sheet contains 0.10% to 0.30% of C, 1.40% to 3.0% of Si, 0.5% to 3.0% of Mn, 0.1% or less of P, 0.05% or less of S, 0.005% to 0.20% of Al, 0.01% or less of N, 0.01% or less of O, as well as Fe and inevitable impurities. The steel sheet has: (i) a ferrite volume fraction of 5% to 35% and a bainitic ferrite and/or tempered martensite volume fraction of 60% or more; (ii) a MA constituent volume fraction of 6% or less (excluding 0%); and (iii) a retained austenite volume fraction of 5% or more.