发明授权
- 专利标题: High-strength steel sheet and high-strength steel pipe excellent in deformability and method for producing the same
- 专利标题(中): 可变形性优异的高强度钢板和高强度钢管及其制造方法
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申请号: US10410014申请日: 2003-04-09
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公开(公告)号: US08070887B2公开(公告)日: 2011-12-06
- 发明人: Hitoshi Asahi , Yasuhiro Shinohara , Takuya Hara
- 申请人: Hitoshi Asahi , Yasuhiro Shinohara , Takuya Hara
- 申请人地址: JP Tokyo
- 专利权人: Nippon Steel Corporation
- 当前专利权人: Nippon Steel Corporation
- 当前专利权人地址: JP Tokyo
- 代理机构: Baker Botts LLP
- 优先权: JP2002-106536 20020409
- 主分类号: C21D9/08
- IPC分类号: C21D9/08 ; C22C38/00 ; C22C38/18
摘要:
The present invention provides a line pipe of, e.g., the API standard X60 to X100 class. The line pipe has an excellent deformability, as well as excellent low temperature toughness and high productivity, a steel plate used as the material of the steel pipe. Methods for producing the steel pipe and the steel plate are also provided. In particular, a high-strength steel plate excellent in the deformability has a ferrite phase is dispersed finely, and accounts for 5% to 40% in area percentage in a low temperature transformation structure mainly composed of a bainite phase. For example, most grain sizes of the ferrite phase are smaller than the average grain size of the bainite phase. A high-strength steel pipe excellent in deformability is also provided, in which a large diameter steel pipe is produced through forming the steel plate into a pipe shape. The steel pipe has the above-referenced structure, and satisfies the conditions that YS/TS is 0.95 or less and YS×uEL is 5,000 or more. Methods for producing such steel plate and steel pipe are also provided.