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:
Apr. 01, 2014
Filed:
Jun. 10, 2010
Kensuke Nagai, Tokyo, JP;
Yasuhiro Shinohara, Tokyo, JP;
Shinya Sakamoto, Tokyo, JP;
Takuya Hara, Tokyo, JP;
Hitoshi Asahi, Tokyo, JP;
Kensuke Nagai, Tokyo, JP;
Yasuhiro Shinohara, Tokyo, JP;
Shinya Sakamoto, Tokyo, JP;
Takuya Hara, Tokyo, JP;
Hitoshi Asahi, Tokyo, JP;
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Abstract
This high-strength steel pipe includes, by mass %, C: 0.02% to 0.09%, Mn: 0.4% to 2.5%, Cr: 0.1% to 1.0%, Ti: 0.005% to 0.03%, Nb: 0.005% to 0.3%, and a balance consisting of Fe and inevitable impurities, in which Si, Al, P, S, and N are limited to 0.6% or less, 0.1% or less, 0.02% or less, 0.005% or less, 0.008% or less, respectively, the bainite transformation index BT is 650° C. or less, and the microstructure thereof is a single bainite microstructure including first bainite and second bainite, the first bainite being a gathered microstructure of bainitic ferrite including no carbide, and the second bainite being a mixed microstructure of bainitic ferrite including no carbide and cementite between the bainitic ferrites.