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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.:

US 10465261 B1

PDFFull Text
Date of Patent:
Nov. 05, 2019

Filed:

Mar. 26, 2015

Steel material for highly deformable line pipes having superior strain aging resistance and superior hic resistance, method for manufacturing same, and welded steel pipe

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Kyono Yasuda, Fukuyama, JP;

Daisuke Mizuno, Kawasaki, JP;

Haruo Nakamichi, Kawasaki, JP;

Nobuyuki Ishikawa, Kawasaki, JP;

Assignee:

JFE STEEL CORPORATION, Tokyo, JP;

Attorney:

Oliff PLC

Primary Examiner:

Helene Klemanski

Int. Cl.
CPC ...
C21D 9/46 (2006.01); C21D 8/02 (2006.01); C21D 8/10 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C22C 38/58 (2006.01); B23K 35/30 (2006.01); C22C 38/00 (2006.01); C22C 38/08 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); B23K 31/02 (2006.01); C22C 38/42 (2006.01); C21D 1/673 (2006.01); B23K 101/10 (2006.01); B23K 103/04 (2006.01);
U.S. Cl.
CPC ...
C21D 9/46 (2013.01); B23K 31/027 (2013.01); C21D 1/673 (2013.01); C21D 8/0226 (2013.01); C21D 8/0263 (2013.01); C22C 38/00 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (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 38/42 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/58 (2013.01); B23K 2101/10 (2018.08); B23K 2103/04 (2018.08); C21D 2211/001 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01);
Abstract

A steel material for highly deformable line pipes that has superior strain aging resistance, superior HIC resistance, and a metallographic structure including ferrite, bainite, and martensite-austenite constituent. The area fraction of the martensite-austenite constituent is 0.5 to 5.0%, and the difference in hardness between the ferrite and the bainite is 60 or more in terms of Vickers hardness. Additionally, the steel material has a uniform elongation of 9% or more and a yield ratio of 90% or less both before a strain aging treatment at a temperature of 300° C. or lower and after the strain aging treatment.

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