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:
Oct. 09, 2018
Filed:
Jun. 23, 2014
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
A seamless steel pipe has a yield strength of 400 MPa or less and excellent HIC resistance. The seamless steel pipe includes: a chemical composition consisting, in mass %, of, C: 0.01 to 0.20%, Si: 0.05 to 0.50%, Mn: 0.3 to 2.0%, P: 0.02% or less, S: 0.01% or less, Cr: 0.02 to 0.2%, sol.Al: 0.001 to 0.100%, O: 0.0050% or less, N: 0.0100% or less, Ca: 0 to 0.0050%, Ti: 0 to 0.012%, and Nb: 0 to 0.012%, the balance being Fe and impurities; and a structure consisting, in area ratio, of 10 to 50% of ferrite and 0 to less than 5% of pearlite, the balance being tempered bainite and/or tempered martensite, and the number of inclusions each having a grain diameter of 50 mm or more is not more than 15 per 100 mm, and the seamless steel pipe has a yield strength of 400 MPa or less.