| 摘要 |
PROBLEM TO BE SOLVED: To provide a grain oriented silicon steel excellent in coating film property and iron loss property, its production method and decarburization annealing equipment used for the method. SOLUTION: The grain oriented silicon steel sheet, which has a composition consisting of, by weight, <=0.005% C, 2.0-7.0% Si, the blance Fe with inevitable impurities, is formed on a surface with an oxidized coating film essentially made of forsterite and an insulation coating film further on its surface. A coating film quantity of the oxidized coating film is 1-4 g/m<2> per one face, a Si peak intensity obtained by a glow discharge emission analysis conducted from the oxidized coating film surface is >=1/2 of an Al peak intensity. Further, a depth from an oxidized coating film surface down to a Si peak position is >=1/10 of depth from an oxidized coating film surface down to a Si peak position, a rate (y%) not causing coating film peeling by 20 mm radius bending and an iron loss property (W) (w/kg) satisfy formula in the following. (y%)>=-122.45 t+112.55 ((t): sheet thickness mm) W (w/kg)<=2.37 t+0.280 ((t): sheet thickness mm). |
