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. 10, 2009
Filed:
Mar. 24, 2004
Hiroshi Nakata, Okayama, JP;
Nobuyuki Kageyama, Tokyo, JP;
Koji Iwata, Okayama, JP;
Tetsuo Shimizu, Chiba, JP;
Chikara Kami, Okayama, JP;
Hiroshi Nakata, Okayama, JP;
Nobuyuki Kageyama, Tokyo, JP;
Koji Iwata, Okayama, JP;
Tetsuo Shimizu, Chiba, JP;
Chikara Kami, Okayama, JP;
JFE Steel Corporation, , JP;
Abstract
A hot-rolled steel strip having superior low temperature toughness and weldability, which is suitably used as a starting material for high strength electric resistance welding pipe, is provided at a low cost without constructing new production facilities and increasing cost. The hot-rolled steel strip is low carbon steel containing at least one of about 0.5.% or less of Cu, about 0.5% or less of Ni, and about 0.5% or less of Mo, wherein Pcm represented by the following equation (1) is 0.17 or less:=(% C)+(% Si)/30+((% Mn)+(% Cu))/20+(% Ni)/60+(% Mo)/7+(% V)/10  Equation (1),(where (% M) indicates the content of element M on a mass percent basis), and the balance includes Fe and incidental impurities. In addition, in the entire microstructure, the ratio of bainitic ferrite, which is a primary phase, is controlled to be about 95 percent by volume or more.