发明授权
- 专利标题: High strength hot rolled steel plate for spiral line pipe superior in low temperature toughness and method of production of same
- 专利标题(中): 用于螺旋线管的高强度热轧钢板优于低温韧性及其生产方法
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申请号: US12449941申请日: 2008-03-04
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公开(公告)号: US09062356B2公开(公告)日: 2015-06-23
- 发明人: Tatsuo Yokoi , Hiroshi Abe , Osamu Yoshida
- 申请人: Tatsuo Yokoi , Hiroshi Abe , Osamu Yoshida
- 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: Kenyon & Kenyon LLP
- 优先权: JP2007-058432 20070308
- 国际申请: PCT/JP2008/054253 WO 20080304
- 国际公布: WO2008/108487 WO 20080912
- 主分类号: C21D9/46
- IPC分类号: C21D9/46 ; C21D6/00 ; C21D8/02 ; C21D9/08
摘要:
The present invention provides hot rolled steel plate for spiral pipe superior in low temperature toughness, thick in gauge, for example, having a plate thickness of 14 mm or more, and having a high strength of the API-X65 standard or more spiral pipe and a method of production of the same, that is, steel plate containing, by mass %, C: 0.01 to 0.1%, Si: 0.05 to 0.5%, Mn: 1 to 2%, P≦0.03%, S≦0.005%, O≦0.003%, Al: 0.005 to 0.05%, N: 0.0015 to 0.006%, Nb: 0.005 to 0.08%, Ti: 0.005 to 0.02%, N−14/48×Ti>0%, Nb−93/14×(N−14/48×Ti>0.005%, Mo: 0.01% to less than 0.1%, Cr: 0.01 to 0.3%, and Cu: 0.01 to 0.3%, and having a balance of Fe and unavoidable impurities, characterized in that an elongation rate of a microstructure unit in a cross-section in the pipe circumferential direction after pipemaking is 2 or less.