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:
Sep. 05, 1989
Filed:
Apr. 08, 1988
Nippon Steel Corporation, Tokyo, JP;
Abstract
In a grain-oriented electromagnetic steel sheet which is produced by a process including a cold-rolling step(s), the final reduction ratio of the cold-rolling step(s) being high, a technical means for refining the secondary recrystallized grains is particularly important. One technical means is the incorporation of tin into silicon steel material. This, however, involves a problem because tin incorporated into silicon steel material deteriorates the surface coating which imparts tension to a grain-oriented electromagnetic steel sheet. The incorporation of copper into silicon steel material has been avoided since it causes secondary recrystallization to be unstable. The present invention is characterized by the combined incorporation of tin and copper into molten steel so as to simultaneously refine the secondary recrystallized grains and to form a good surface coating. The grain-oriented electromagnetic steel sheet of the present invention contains from 2.5% to less than 4.0% of silicon, from 0.03% to 0.15% of manganese, from 0.03% to 0.5% of tin, and from 0.02% to less than 0.3% of copper.