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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 11313007 B1

PDFFull Text
Date of Patent:
Apr. 26, 2022

Filed:

Sep. 13, 2017

High-strength seamless steel pipe for oil country tubular goods, and method for producing the same

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Masao Yuga, Tokyo, JP;

Mitsuhiro Okatsu, Tokyo, JP;

Assignee:

JFE Steel Corporation, Tokyo, JP;

Attorney:

RatnerPrestia

Primary Examiner:

Jie Yang

Int. Cl.
CPC ...
C21D 6/02 (2006.01); C21D 8/10 (2006.01); C21D 9/08 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/22 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/32 (2006.01); C22C 38/44 (2006.01); C22C 38/46 (2006.01); C22C 38/48 (2006.01); C22C 38/54 (2006.01); C22C 38/20 (2006.01); C22C 38/28 (2006.01); C22C 38/42 (2006.01); C22C 38/50 (2006.01);
U.S. Cl.
CPC ...
C21D 8/105 (2013.01); C21D 9/085 (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 38/20 (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); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/54 (2013.01); C21D 2211/004 (2013.01); C21D 2211/008 (2013.01);
Abstract

Provided herein is a high-strength seamless steel pipe containing a particular chemical composition. The volume fraction of tempered martensite is 90% or more in terms of a volume fraction. The number of nitride inclusions with a particle diameter of 4 μm or more is 50 or less per 100 mm, the number of nitride inclusions with a particle diameter of less than 4 μm is 500 or less per 100 mm, the number of oxide inclusions with a particle diameter of 4 μm or more is 40 or less per 100 mm, and the number of oxide inclusions with a particle diameter of less than 4 μm is 400 or less per 100 mmin a cross section perpendicular to a rolling direction.

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