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. 15, 1985
Filed:
Aug. 04, 1982
Koichi Fujiwara, Himeji, JP;
Tomohiko Sakai, Himeji, JP;
Yoneo Yamada, Himeji, JP;
Kazutaka Higashine, Himeji, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
In the production of a grain-oriented electromagnetic steel strip or sheet having a low watt loss, a silicon steel slab containing not more than 0.085% by weight of carbon, from 2.0% to 4.0% by weight of silicon, from 0.030% to 0.090% by weight of manganese, and from 0.010% to 0.060% by weight of sulfur is conventionally hot-rolled, cold-rolled, and final-annealed. However, this production process involves some problems in regard to the uniformity of the magnetic properties along the full length of the coiled strip. According to the present invention, a silicon steel slab additionally contains from 0.02% to 0.2% by weight of copper, the exit temperature during the finishing-hot-rolling step is controlled in such a manner that the temperature of the top portion of the hot-rolled strip is in the range of from 900.degree. C. to 1050.degree. C. and the temperature of the middle and bottom portions thereof is in the range of from 950.degree. C. and 1150.degree. C., and final cold-rolling is carried out at a reduction ratio of from 50% to 80%, with the result that the final product has good and very uniform magnetic properties over the full length thereof.