发明申请
- 专利标题： Seamless steel pipe for oil wells excellent in sulfide stress cracking resistance and method for producing the same
- 专利标题（中）： 耐硫化应力开裂性优良的油井用无缝钢管及其制造方法
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申请号： US11494608申请日： 2006-07-28
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公开(公告)号： US20060266448A1公开(公告)日： 2006-11-30
- 发明人: Yuji Arai , Tomohiko Omura , Keiichi Nakamura
- 申请人： Yuji Arai , Tomohiko Omura , Keiichi Nakamura
- 优先权： JP2004-023470 20040130
- 主分类号： C21D9/08
- IPC分类号： C21D9/08 ; C22C38/32
摘要：
A high-strength seamless steel pipe for oil wells excellent in sulfide stress cracking resistance which comprises, on the percent by mass basis, C: 0.1 to 0.20%, Si: 0.05 to 1.0%, Mn: 0.05 to 1.0%, Cr: 0.05 to 1.5%, Mo: 0.05 to 1.0%, Al: 0.10% or less, Ti: 0.002 to 0.05% and B: 0.0003 to 0.005%, with a value of equation “C+(Mn/6)+(Cr/5)+(Mo/3)” of 0.43 or more, with the balance being Fe and impurities, and in the impurities P: 0.025% or less, S: 0.010% or less and N: 0.007% or less. The seamless steel pipe may contain a specified amount of one or more element(s) of V and Nb, and/or a specified amount of one or more element(s) of Ca, Mg and REM. The seamless steel pipe can be produced at a low cost by adapting an in-line tube making and heat treatment process having a high production efficiency since a reheating treatment for refinement of grains is not required.