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. 30, 2024
Filed:
Oct. 01, 2019
Nippon Steel Corporation, Tokyo, JP;
Kyohei Kanki, Tokyo, JP;
Masayuki Sagara, Tokyo, JP;
Yusaku Tomio, Tokyo, JP;
Daisuke Matsuo, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
The seamless steel pipe according to the present disclosure includes a chemical composition consisting of, in mass %, C: 0.030% or less, Si: 1.00% or less, Mn: 1.00% or less, P: 0.030% or less, S: 0.0050% or less, Al: 0.001 to 0.100%, N: 0.0500% or less, O: 0.050% or less, Ni: 5.00 to 6.50%, Cr: more than 10.00 to 13.40%, Cu: more than 1.50 to 3.50%, Mo: 1.00 to 4.00%, V: 0.01 to 1.00%, Ti: 0.050 to 0.300%, and Co: 0.010 to 0.300%, with the balance being Fe and impurities, and satisfying Formula (1), wherein a depassivation pH of an inner surface is 3.00 or less.Cr+2.0 Mo+0.5 Ni+2.0 Cu+0.5 Co≥20.0 (1)