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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 12565697 B1

PDFFull Text
Date of Patent:
Mar. 03, 2026

Filed:

Mar. 23, 2021

Electric resistance welded steel pipe and method for producing the same

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Akihide Matsumoto, Tokyo, JP;

Atsushi Matsumoto, Tokyo, JP;

Shinsuke Ide, Tokyo, JP;

Takatoshi Okabe, Tokyo, JP;

Assignee:

JFE Steel Corporation, Tokyo, JP;

Attorney:

Buchanan Ingersoll & Rooney PC

Primary Examiner:

Anthony M Liang

Int. Cl.
CPC ...
C22C 38/04 (2006.01); B21C 37/08 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C21D 8/0221 (2026.01); C21D 8/0247 (2026.01); C21D 8/10 (2006.01); C21D 9/08 (2006.01); C22C 38/02 (2006.01); C22C 38/06 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01);
U.S. Cl.
CPC ...
C22C 38/04 (2013.01); B21C 37/08 (2013.01); C21D 6/005 (2013.01); C21D 8/0226 (2013.01); C21D 8/0263 (2013.01); C21D 8/105 (2013.01); C21D 9/08 (2013.01); C22C 38/02 (2013.01); C22C 38/06 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01);
Abstract

An electric resistance welded steel pipe includes a base metal zone and an electric resistance welded zone. The base metal zone has a chemical composition containing, by mass, predetermined amounts of C, Si, Mn, P, S, Al, N, Nb, V, and Ti, with the balance being Fe and incidental impurities. The steel microstructure of the wall-thickness center of the base metal zone includes ferrite and bainite such that the total volume fraction of the ferrite and the bainite in the steel microstructure is 70% or more, with the balance being one or more selected from pearlite, martensite, and austenite. The steel microstructure has an average grain size of 7.0 m or less and a dislocation density of 1.0×10to 6.0×10m. The residual stress generated in the inner and outer surfaces of the pipe in the axial direction is 150 MPa or less.

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