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. 02, 1993
Filed:
Nov. 05, 1991
Nippon Steel Corporation, Tokyo, JP;
Abstract
A process for producing a grain-oriented electrical steel sheet having improved magnetic and surface film properties, comprising: using an electrical silicon steel slab containins S in an extremely small amount of 0.012 wt % or less and Mn in a limited range of 0.08 to 0.45 wt %; heating the slab to a relatively low temperature of not higher than 1200.degree. C.; hot-rolling the slab to form a hot-rolled strip; cold-rolling the strip to a thickness of a final product sheet; decarburization-annealing the cold-rolled strip; nitriding the strip while it is travelling; applying an annealing separator to the strip; and final texture-annealing the strip by heating the strip to a first temperature of from 800.degree. to 850.degree. C. in an atmosphere of (N.sub.2 +Ar).gtoreq.30 vol % with 25 vol % or more N.sub.2 and the remainder H.sub.2 and subsequently heating from the first temperature to above 1200.degree. C. in a conventional atmosphere.