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. 03, 2017
Filed:
Aug. 17, 2012
Atsushi Soma, Tokyo, JP;
Tomohiko Omura, Tokyo, JP;
Yuji Arai, Tokyo, JP;
Mitsuhiro Numata, Tokyo, JP;
Toru Takayama, Tokyo, JP;
Masanao Seo, Tokyo, JP;
Atsushi Soma, Tokyo, JP;
Tomohiko Omura, Tokyo, JP;
Yuji Arai, Tokyo, JP;
Mitsuhiro Numata, Tokyo, JP;
Toru Takayama, Tokyo, JP;
Masanao Seo, Tokyo, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
To provide an oil-well steel pipe having excellent SSC resistance. The oil-well steel pipe according to the present invention contains, by mass percent, C: 0.15 to 0.35%, Si: 0.1 to 0.75%, Mn: 0.1 to 1.0%, Cr: 0.1 to 1.7%, Mo: 0.1 to 1.2%, Ti: 0.01 to 0.05%, Nb: 0.010 to 0.030%, Al: 0.01 to 0.1%, P: at most 0.03%, S: at most 0.01%, N: at most 0.007%, and O: at most 0.01%, the balance being Fe and impurities. The Ti content and the Nb content in a residue obtained by bromine-methanol extraction satisfy equation (1):100×[Nb]/([Ti]+[Nb])≦27.5  (1)where the Ti content (mass %) and the Nb content (mass %) in the residue are substituted for [Ti] and [Nb].