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:
Sep. 04, 2007
Filed:
Jul. 15, 2005
Mitsuhiro Numata, Kamisu-machi, JP;
Tomohiko Omura, Kishiwada, JP;
Yoshihiko Higuchi, Kashima, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A steel for steel pipes which comprises, on the percent by mass basis, C: 0.2 to 0.7%, Si: 0.01 to 0.8%, Mn: 0.1 to 1.5%, S: 0.005% or less, P: 0.03% or less, Al: 0.0005 to 0.1%, Ti: 0.005 to 0.05%, Ca: 0.0004 to 0.005%, N: 0.007% or less, Cr: 0.1 to 1.5%, Mo: 0.2 to 1.0%, Nb: 0 to 0.1%, Zr: 0 to 0.1%, V: 0 to 0.5% and B: 0 to 0.005%, with the balance being Fe and impurities, in which non-metallic inclusions containing Ca, Al, Ti, N, O, and S are present, and in the said inclusions (Ca %)/(Al %) is 0.55 to 1.72, and (Ca %)/(Ti %) is 0.7 to 19 can be used as a raw material for oil country tubular goods, being used at a greater depth and in severer corrosive circumstances, such as casings and tubings for oil and/or natural gas wells, drilling pipes and drilling collars for excavation, and the like.