发明授权
- 专利标题: Heat-treated steel wire for high strength spring
- 专利标题(中): 用于高强度弹簧的热处理钢丝
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申请号: US10467493申请日: 2002-02-07
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公开(公告)号: US07575646B2公开(公告)日: 2009-08-18
- 发明人: Masayuki Hashimura , Takanari Miyaki , Hiroshi Hagiwara , Hiroaki Hayashi , Shouich Suzuki , Katsuaki Shiiki , Noriyuki Yamada , Seiichi Koike
- 申请人: Masayuki Hashimura , Takanari Miyaki , Hiroshi Hagiwara , Hiroaki Hayashi , Shouich Suzuki , Katsuaki Shiiki , Noriyuki Yamada , Seiichi Koike
- 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: JP2001-030511 20010207
- 国际申请: PCT/JP02/01049 WO 20020207
- 国际公布: WO02/063055 WO 20020815
- 主分类号: C22C38/22
- IPC分类号: C22C38/22
摘要:
The present invention provides a steel wire, for springs excellent in coiling property while having a high strength, as a heat treated steel wire for high strength springs, characterized by: comprising, in mass, C: 0.75 to 0.85%, Si: 1.5 to 2.5%, Mn: 0.5 to 1.0%, Cr: 0.3 to 1.0%, P: not more than 0.015%, S: not more than 0.015%, N: 0.001 to 0.007%, W: 0.05 to 0.3%, and the balance consisting of Fe and unavoidable impurities; having a tensile strength of not less than 2,000 MPa; spheroidal carbides, composed of mainly cementite, observed in a microscopic visual field satisfying the area percentage of the spheroidal carbides not less than 0.2 μm in circle equivalent diameter being not more than 7%, the density of the spheroidal carbides 0.2 to 3 μm in circle equivalent diameter being not more than 1 piece/μm2, and the density of the spheroidal carbides over 3 μm in circle equivalent diameter being not more than 0.001 piece/μm2; the prior austenite grain size number being #10 or larger; the content of the retained austenite being not more than 12 mass %; the maximum diameter of carbides being not more than 15 μm; and the maximum diameter of oxides being not more than 15 μm.
公开/授权文献
- US20040112473A1 Heat-treated steel wire for high strength spring 公开/授权日:2004-06-17