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:
Mar. 01, 2011
Filed:
Feb. 21, 2008
Kenji Kobayashi, Nishinomiya, JP;
Tomohiko Omura, Kishiwada, JP;
Kunio Kondo, Sanda, JP;
Yuji Arai, Amagasaki, JP;
Nobuyuki Hisamune, Kinokawa, JP;
Kenji Kobayashi, Nishinomiya, JP;
Tomohiko Omura, Kishiwada, JP;
Kunio Kondo, Sanda, JP;
Yuji Arai, Amagasaki, JP;
Nobuyuki Hisamune, Kinokawa, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A seamless steel pipe for line pipe having high strength and stable toughness and having resistance to sulfide corrosion cracking at low temperatures to room temperature is provided. A seamless steel pipe according to the present invention has a chemical composition comprising, in mass percent, C: 0.03-0.08%, Si: 0.05-0.5%, Mn: 1.0-3.0%, Mo: greater than 0.4% to 1.2%, Al: 0.005-0.100%, Ca: 0.001-0.005%, a remainder of Fe and impurities including N, P, S, O, and Cu, with the impurities containing at most 0.01% of N, at most 0.05% of P, at most 0.01% of S, at most 0.01% of O, and at most 0.1% of Cu, and having a microstructure comprising a bainitic-martensitic dual phase structure.