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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 9322087 B1

PDFFull Text
Date of Patent:
Apr. 26, 2016

Filed:

Jul. 08, 2015

Stainless steel for oil well, stainless steel pipe for oil well, and method of manufacturing stainless steel for oil well

Applicant:

Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;

Inventors:

Hideki Takabe, Osaka, JP;

Kunio Kondo, Sanda, JP;

Hisashi Amaya, Kyoto, JP;

Taro Ohe, Izumiotsu, JP;

Yohei Otome, Amagasaki, JP;

Assignee:

NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;

Attorney:

Clark & Brody

Primary Examiner:

Brian Walck

Int. Cl.
CPC ...
C21D 8/00 (2006.01); C22C 38/50 (2006.01); C21D 8/02 (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 38/42 (2006.01); C22C 38/44 (2006.01); F16L 9/02 (2006.01); C21D 6/00 (2006.01); C22C 38/46 (2006.01); C22C 38/48 (2006.01);
U.S. Cl.
CPC ...
C22C 38/50 (2013.01); C21D 6/004 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/005 (2013.01); C21D 8/0205 (2013.01); C21D 8/105 (2013.01); C21D 9/08 (2013.01); C21D 9/085 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/004 (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); F16L 9/02 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01);
Abstract

The chemical composition of a stainless steel in accordance with the present invention consists of C: not more than 0.05%, Si: not more than 0.5%, Mn: 0.01 to 0.5%, P: not more than 0.04%, S: not more than 0.01%, Cr: more than 16.0 and not more than 18.0%, Ni: more than 4.0 and not more than 5.6%, Mo: 1.6 to 4.0%, Cu: 1.5 to 3.0%, Al: 0.001 to 0.10%, and N: not more than 0.050%, the balance being Fe and impurities, and satisfies Formulas (1) and (2). Also, the micro-structure thereof contains a martensitic phase and a ferritic phase having a volume ratio of 10 to 40%, and the ferritic phase distribution ratio is higher than 85%.Cr+Cu+Ni+Mo ≧  ()−(C+N)+Mn+Ni+Cu/(Cr+Mo) ≦−  ()

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