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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 12742233 B1

PDFFull Text
Date of Patent:
Sep. 22, 2026

Filed:

Sep. 29, 2022

Duplex stainless steel pipe

Applicant:

Nippon Steel Corporation, Tokyo, JP;

Inventors:

Seiya Okada, Tokyo, JP;

Yuji Arai, Tokyo, JP;

Daisuke Matsuo, Tokyo, JP;

Assignee:

NIPPON STEEL CORPORATION, Tokyo, JP;

Attorney:

Greer Burns & Crain Ltd.

Primary Examiner:

Vanessa T Luk

Int. Cl.
CPC ...
C22C 38/44 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/42 (2006.01); C22C 38/46 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); C22C 38/52 (2006.01); C22C 38/54 (2006.01); C22C 38/58 (2006.01); C22C 38/60 (2006.01); F16L 9/02 (2006.01);
U.S. Cl.
CPC ...
C22C 38/60 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (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 38/52 (2013.01); C22C 38/54 (2013.01); C22C 38/58 (2013.01); F16L 9/02 (2013.01);
Abstract

The duplex stainless steel pipe according to the present disclosure consists of, by mass %, C: 0.030% or less, Si: 1.00% or less, Mn: 0.10 to 7.00%, P: 0.040% or less, S: 0.0050% or less, Cr: 20.0 to 30.0%, Ni: 4.2 to 10.0%, Mo: 0.5 to 5.0%, Cu: 0.5 to 6.0%, N: less than 0.350%, O: 0.0005 to 0.0100%, and Ca: 0.0005 to 0.0100%, with the balance being Fe and impurities. A microstructure consists of, in volume ratio, ferrite in an amount of 30 to 80% with the balance being austenite. A yield strength is 552 MPa or more. A number density of Ca oxides having an equivalent circular diameter of 2.0 μm or more is 500/100 mmor more.

Find Patent Forward Citations

Okada, Seiya. (2026). Duplex stainless steel pipe (U.S. Patent No. 12742233). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/12742233

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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