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:
Jan. 07, 1992
Filed:
Oct. 17, 1988
Masayuki Kinoshita, Tokyo, JP;
Akihiko Nishimoto, Tokyo, JP;
Toshiaki Urabe, Tokyo, JP;
Akira Sakamoto, Tokyo, JP;
Nippon Kokan Kabushiki Kaisha, Tokyo, JP;
Abstract
A method for producing cold-rolled steel sheets which comprises the steps of: producing slabs containing 0.001-0.003 wt. % C, 0.004 wt. % or less N and 0.03-0.20 wt. % P, providing that P(wt. %).times.N(wt. %).ltoreq.3.times.10.sup.-4 wt. % is satisfied; hot-rolling the slabs into hot-rolled steel strips; cold-rolling the hot-rolled steel strips at 60-95% reduction ratio into cold-rolled steel strips; and annealing continuously the cold-rolled strips at temperature of recrystallization temperature to Ac.sub.3 transformation point temperature. The slabs further include 0.0005-0.0030 wt. % B. The hot-rolling is performed at finishing temperature ranging Ar.sub.3 transfromation point to Ar.sub.3 transformation +100.degree. C., at cooling temperature of 750.degree. C. and less.