The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 01, 2019
Filed:
Feb. 04, 2014
Applicant:
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Inventors:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C22C 38/04 (2006.01); C22C 38/38 (2006.01); C21D 9/08 (2006.01); C22C 38/00 (2006.01); C22C 38/12 (2006.01); C22C 38/02 (2006.01); C22C 38/06 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C22C 38/22 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01); B23K 11/087 (2006.01); B23K 11/093 (2006.01); C22C 38/08 (2006.01); F16L 9/02 (2006.01);
U.S. Cl.
CPC ...
C22C 38/38 (2013.01); B23K 11/0873 (2013.01); B23K 11/0935 (2013.01); C21D 9/08 (2013.01); C22C 38/00 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C22C 38/22 (2013.01); C22C 38/24 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C22C 38/32 (2013.01); F16L 9/02 (2013.01);
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.