| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ultra-low iron loss unidirectional silicon steel sheet which has an extremely superior iron loss property and a superior compressive stress property of magnetostriction in a stable manner at low cost. SOLUTION: A solution containing Si compound is applied on the surface of an annealed unidirectional silicon steel sheet having a thickness of 0.05-0.5 mm so as to allow a slight amount of Si to adhere thereto in an activated state. And then, an exposure operation is preferably performed in an N- containing non-oxidizing atmosphere, or a short-time heating operation is performed in a non-oxidizing atmosphere, so as to form an extremely thin nitrogen and oxygen layer containing Si on the surface of the steel sheet. After a while, a tensile insulating coating is formed in accordance with a conventional method. |
