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.:
Date of Patent:
Apr. 19, 2022
Filed:
Jan. 23, 2018
Jfe Steel Corporation, Tokyo, JP;
Yuichi Kamo, Tokyo, JP;
Masao Yuga, Tokyo, JP;
Kenichiro Eguchi, Tokyo, JP;
Yasuhide Ishiguro, Tokyo, JP;
JFE Steel Corporation, Tokyo, JP;
Abstract
Provided herein is a high-strength stainless steel seamless pipe for oil country tubular goods. The high-strength stainless steel seamless pipe having a yield strength of 862 MPa or more contains, in mass %, C:0.05% or less, Si: 0.5% or less, Mn: 0.15 to 1.0%, P: 0.030% or less, S: 0.005% or less, Cr: 14.5 to 17.5%, Ni: 3.0 to 6.0%, Mo: 2.7 to 5.0%, Cu: 0.3 to 4.0%, W: 0.1 to 2.5%, V: 0.02 to 0.20%, Al: 0.10% or less, N: 0.15% or less, B: 0.0005 to 0.0100%, and the balance Fe and unavoidable impurities, and in which the composition satisfies specific formulas. The stainless steel pipe has more than 45% martensite phase, 10 to 45% ferrite phase, and 30% or less retained austenite phase. The ferrite grains have a maximum crystal grain size of 500 μm or less.