| 摘要 |
PURPOSE:To remarkably decrease an iron loss with good safety by radiating plasma flames to a grain oriented silicon steel sheet subjected to finish annealing at the current density having a specific relation with the film quantity on the surface thereof. CONSTITUTION:The plasma flames at the current density W(A/mm<2>) satisfying the equation are radiated onto the grain oriented silicon steel sheet subjected to the finish annealing in the direction intersecting with the rolling direction of the steel sheet according to the quantity of the film formed on the surface thereof. F0 in the equation is the oxygen coating weight (g/m<2>) indicating the magnitude of the film quantity. The iron loss is, therefore, considerably decreased by measuring the film quantity, i.e., oxygen coating weight, after the finish annealing and radiating the plasma flames of the current density determined by the measured oxygen coating weight. |
