| 摘要 |
PROBLEM TO BE SOLVED: To effectively reduce noise feared when a grain-oriented electromagnetic steel sheet is used by being laminated on an iron core of transformer, etc. by adding contrivance to insulating coating process.SOLUTION: Distortion is given to the surface of the grain-oriented electromagnetic steel sheet already insulating-coated and finish-annealed, by at least one of an optical means, a mechanical means, a chemical means and a thermal means, and insulating coating is given only to the distortion-given surface again, in the grain-oriented electromagnetic steel sheet. In this steel sheet, a solid matter is added in insulating coating, and the solid matter is not exserted in the distortion-given surface, while the solid matter is exserted in the surface opposite to the distortion-given surface. |
