- 专利标题: Hot-rolled steel sheet and manufacturing method thereof
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申请号: US14370158申请日: 2012-12-27
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公开(公告)号: US10087499B2公开(公告)日: 2018-10-02
- 发明人: Hiroshi Shuto , Tatsuo Yokoi , Yuuki Kanzawa , Nobuhiro Fujita , Ryohta Niiya , Shinya Saitoh
- 申请人: NIPPON STEEL & SUMITOMO METAL CORPORATION
- 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: JP2012-000484 20120105
- 国际申请: PCT/JP2012/083918 WO 20121227
- 国际公布: WO2013/103125 WO 20130711
- 主分类号: C21D8/02
- IPC分类号: C21D8/02 ; C22C38/06 ; C22C38/00 ; C22C38/02 ; C22C38/04 ; C22C38/12 ; C22C38/14 ; B32B15/01 ; C22C38/08 ; C22C38/20 ; C22C38/26 ; C22C38/28 ; C21D9/46 ; C21D1/25 ; C23C2/02 ; C25D5/36
摘要:
There are provided a high-strength hot-rolled steel sheet securing low-temperature toughness and having excellent stretch flangeability by controlling a structural fraction and a hardness difference among structures, and a manufacturing method thereof. A hot-rolled steel sheet contains: C: 0.01 to 0.2%; Si: 0.001 to 2.5% or less; Mn: 0.10 to 4.0% or less; P: 0.10% or less; S: less than 0.03%; Al: 0.001 to 2.0%; N: less than 0.01%; Ti: (0.005+48/14[N]+48/32[S]) % or more and 0.3% or less; Nb: 0 to 0.06%; Cu: 0 to 1.2%; Ni: 0 to 0.6%; Mo: 0 to 1%; V: 0 to 0.2%; Cr: 0 to 2%; Mg: 0 to 0.01%; Ca: 0 to 0.01%; REM: 0 to 0.1%; and B: 0 to 0.002%, and has: an texture in which, at a central portion of a sheet thickness located between ⅜ to ⅝ thickness positions of the sheet thickness from a surface of the steel sheet, an average value of X-ray random intensity ratios of a group of {100} to {223} orientations of a sheet plane is 6.5 or less and an X-ray random intensity ratio of a {332} crystal orientation is 5.0 or less; and a microstructure in which a total area ratio of tempered martensite, martensite and lower bainite is more than 85%, and an average crystal grain diameter is 12.0 μm or less.
公开/授权文献
- US20150017471A1 HOT-ROLLED STEEL SHEET AND MANUFACTURING METHOD THEREOF 公开/授权日:2015-01-15
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