Invention Grant
- Patent Title: Steel pipe
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Application No.: US15108950Application Date: 2014-02-04
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Publication No.: US10167538B2Publication Date: 2019-01-01
- Inventor: Yosuke Kiyota , Takaaki Fukushi , Hideyuki Nakamura
- Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
- Applicant Address: JP Tokyo
- Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
- Current Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Birch, Stewart, Kolasch & Birch, LLP
- International Application: PCT/JP2014/052567 WO 20140204
- International Announcement: WO2015/118610 WO 20150813
- Main IPC: C22C38/04
- IPC: C22C38/04 ; C22C38/38 ; C21D9/08 ; C22C38/00 ; C22C38/12 ; C22C38/02 ; C22C38/06 ; C22C38/14 ; C22C38/16 ; C22C38/22 ; C22C38/24 ; C22C38/26 ; C22C38/28 ; C22C38/32 ; B23K11/087 ; B23K11/093 ; C22C38/08 ; F16L9/02

Abstract:
A steel pipe, consisting of, in terms of mass %: from 0.06% to 0.25% of C, 0.50% or less of Si, 1.00% to 1.80% of Mn, 0.030% or less of P, 0.020% or less of S, 0.08% or less of Al, 0.008% or less of N, 0.080% or less of Nb, and a remainder consisting of Fe and unavoidable impurities, wherein a compressive residual stress at an outer surface measured by an X-ray method is 250 MPa or more, and a compressive residual stress at a position at a depth of 1 mm from the outer surface measured by the X-ray method is 70% or more of the compressive residual stress at the outer surface measured by the X-ray method.
Public/Granted literature
- US20160319404A1 STEEL PIPE Public/Granted day:2016-11-03
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