发明授权
- 专利标题： High-strength steel sheet and high-strength zinc-coated steel sheet which have excellent ductility and stretch-flangeability and manufacturing method thereof
- 专利标题（中）： 具有优异的延展性和拉伸凸缘性的高强度钢板和高强度镀锌钢板及其制造方法
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申请号： US13822746申请日： 2011-09-16
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公开(公告)号： US09139885B2公开(公告)日： 2015-09-22
- 发明人: Hiroyuki Kawata , Naoki Maruyama , Akinobu Murasato , Naoki Yoshinaga , Chisato Wakabayashi , Noriyuki Suzuki
- 申请人： Hiroyuki Kawata , Naoki Maruyama , Akinobu Murasato , Naoki Yoshinaga , Chisato Wakabayashi , Noriyuki Suzuki
- 申请人地址： JP Tokyo
- 专利权人： NIPPON STEEL & SUMITOMO METAL CORPORATION
- 当前专利权人： NIPPON STEEL & SUMITOMO METAL CORPORATION
- 当前专利权人地址： JP Tokyo
- 代理机构： Birch, Stewart, Kolasch & Birch, LLP
- 优先权： JP2010-208329 20100916; JP2010-208330 20100916
- 国际申请： PCT/JP2011/071222 WO 20110916
- 国际公布： WO2012/036269 WO 20120322
- 主分类号： C21D8/02
- IPC分类号： C21D8/02 ; C22C38/40 ; C25D5/10 ; B32B15/00 ; C21D9/46 ; C22C38/00 ; C22C38/02 ; C22C38/06 ; C22C38/38 ; C23C2/06 ; C23C2/40 ; C22C38/04 ; C22C38/08 ; C22C38/12 ; C22C38/14 ; C22C38/16 ; C22C38/34 ; C22C38/58 ; C23C2/02 ; C23C2/28 ; C25D3/22 ; C25D5/36 ; C25D5/50 ; C25D3/56
摘要：
This high-strength steel sheet includes by mass percentage: 0.05 to 0.4% of C; 0.1 to 2.5% of Si; 1.0 to 3.5% of Mn; 0.001 to 0.03% of P; 0.0001 to 0.01% of S; 0.001 to 2.5% of Al; 0.0001 to 0.01% of N; 0.0001 to 0.008% of O; and a remainder composed of iron and inevitable impurities, wherein a steel sheet structure contains by volume fraction 10 to 50% of a ferrite phase, 10 to 50% of a tempered martensite phase, and a remaining hard phase, wherein a 98% hardness is 1.5 or more times as high as a 2% hardness in a range from ⅛ to ⅜ of a thickness of the steel sheet, wherein a kurtosis K* of the hardness distribution between the 2% hardness and the 98% hardness is −1.2 to −0.4, and wherein an average crystal grain size in the steel sheet structure is 10 μm or less.