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:
Jun. 05, 2001
Filed:
Dec. 09, 1999
Applicant:
Inventors:
Koichiro Fujita, Tokyo, JP;
Yasushi Tanaka, Tokyo, JP;
Hironori Ninomiya, Tokyo, JP;
Tatsuhiko Hiratani, Tokyo, JP;
Shoji Kasai, Tokyo, JP;
Assignee:
NKK Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01F 1/04 ;
U.S. Cl.
CPC ...
H01F 1/04 ;
Abstract
A silicon steel sheet contains 0.01 wt. % or less C, 4 to 10 wt. % Si, 0.5 wt. % or less Mn, 0.01 wt. % or less P, 0.01 wt. % or less S, 0.2 wt. % or less sol. Al, 0.01 wt. % or less N, 0.02 wt. % or less O and the balance being Fe. The silicon steel sheet has grain boundaries and carbides which are precipitated on the grain boundaries. The carbides have an area of 20% or less to an area of the grain boundaries. The steel sheet is cooled at a cooling speed of 5° C./sec. or more in a temperature range of from 300 to 700° C.