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:
Aug. 07, 2007
Filed:
Mar. 02, 2004
Katsumi Nakajima, Fukuyama, JP;
Takeshi Fujita, Fukuyama, JP;
Toshiaki Urabe, Fukuyama, JP;
Yuji Yamasaki, Fukuyama, JP;
Fusato Kitano, Fukuyama, JP;
Katsumi Nakajima, Fukuyama, JP;
Takeshi Fujita, Fukuyama, JP;
Toshiaki Urabe, Fukuyama, JP;
Yuji Yamasaki, Fukuyama, JP;
Fusato Kitano, Fukuyama, JP;
NKK Corporation, Tokyo, JP;
Abstract
A steel sheet containing 0.004 to 0.02% C, 1.0% or less Si, 0.7 to 3.0% Mn, 0.02 to 0.15% P, 0.02% or less S, 0.01 to 0.1% Al, 0.004% or less N, 0.2% or less Nb, by mass %, optionally Ti, Bi or at least one element selected from the group consisting of Cr Mo, Ni and Cu, and the balance being Fe; the Nb content satisfying a formula of(12/93)×Nb*/C≧1.0,wherein Nb*=Nb−(93/14)×N, and wherein C, N and Nb designate the content in mass % of carbon, nitrogen and niobium, respectively; and a yield strength and an average grain size of the ferritic grains which satisfy a formula of≦−120+1280,wherein YP designates yield strength in MPa, and d designates an average size of ferritic grains in μm.