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:
Dec. 22, 1992
Filed:
Oct. 28, 1991
Michiro Komatsubara, Chiba, JP;
Toshio Sadayori, Chiba, JP;
Katsuo Iwamoto, Chiba, JP;
Yasuyuki Hayakawa, Chiba, JP;
Takahiro Kan, Chiba, JP;
Kawasaki Steel Corporation, , JP;
Abstract
An oriented silicon steel sheet having a very high magnetic flux density is produced from an oriented silicon steel containing AlN as the main inhibitor and also containing Sb by a method adapted to prevent the loss of the inhibiting ability of the surface layer of the steel, and to improve cooling conditions in annealing before the final cold rolling. The steel is hot rolled, subjected to at least one time the combination of annealing and cold rolling wherein the final cold rolling is performed with a rolling reduction of about 80 to 95%, subjected to decarburization and primary recrystallization annealing, and subjected to, after coating an annealing separation agent, final finish annealing. Before annealing is performed before the final cold rolling, a nitriding promoter is applied to the surface of the steel sheet, and the partial-pressure ratio of N.sub.2 in the atmosphere for that annealing is adjusted to a value of not less than about 20%. In this way, it is possible to stably produce an oriented silicon steel sheet that exhibits a high magnetic flux density even with a small sheet thickness.