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:
Nov. 27, 2012
Filed:
Apr. 20, 2011
Yuji Arai, Amagasaki, JP;
Takashi Takano, Wakayama, JP;
Yuji Arai, Amagasaki, JP;
Takashi Takano, Wakayama, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A seamless steel pipe of a low-alloy steel consisting, by mass %, of C: 0.10 to 0.20%, Si: 0.05 to 1.0%, Mn: 0.05 to 1.2%, Ni: 0.02 to 1.5%, Cr: 0.50 to 1.50%, Mo: 0.50 to 1.50%, Nb: 0.002 to 0.10%, Al: 0.005 to 0.10%, and either or both of Ti: 0.003 to 0.050% and V: 0.01 to 0.20%, the balance being Fe and impurities, the impurities containing 0.025% or less of P, 0.005% or less of S, 0.007% or less of N, and less than 0.0003% of B, wherein the tensile strength is 950 MPa or more and the yield strength is 850 MPa or more, and the Charpy absorbed energy at −40° C. is 60 J or more. This seamless steel pipe may further contain one or more of Cu: 0.02 to 1.0%, Ca: 0.0005 to 0.0050%, and Mg: 0.0005 to 0.0050%. The present invention also provides a method for manufacturing the above-described seamless steel pipe.