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.

Date of Patent:
Jul. 16, 2024

Filed:

Sep. 18, 2019
Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Masatoshi Aratani, Tokyo, JP;

Ryoji Matsui, Tokyo, JP;

Tomonori Kondou, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D 9/08 (2006.01); C21D 8/10 (2006.01); C21D 9/00 (2006.01); C21D 9/50 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/42 (2006.01); C22C 38/58 (2006.01);
U.S. Cl.
CPC ...
C21D 9/085 (2013.01); C21D 8/10 (2013.01); C21D 9/0012 (2013.01); C21D 9/505 (2013.01); C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/42 (2013.01); C22C 38/58 (2013.01); C21D 2211/001 (2013.01); C21D 2211/005 (2013.01);
Abstract

Provided is an electric resistance welded steel pipe or tube that develops no quench cracks despite having carbon content of 0.40% or more and has excellent fatigue strength. An electric resistance welded steel pipe or tube comprises: a chemical composition containing, in mass %, C: 0.40% to 0.55%, Si: 0.10% to 1.0%, Mn: 0.10% to 2.0%, P: 0.10% or less, S: 0.010% or less, Al: 0.010% to 0.100%, Cr: 0.05% to 0.30%, Ti: 0.010% to 0.050%, B: 0.0005% to 0.0030%, Ca: 0.0001% to 0.0050%, and N: 0.0005% to 0.0050%, with a balance consisting of Fe and inevitable impurities; and a ferrite decarburized layer at each of an outer surface and an inner surface, the ferrite decarburized layer having a depth of 20 μm to 50 μm from the surface.


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