| 摘要 |
PURPOSE:To obtain a silicon steel sheet free from deterioration in magnetic properties after stress relief annealing by consumers, increased in productivity, and causing no rise in energy costs by specifying furnace temp. at the time of passing a temper rolled steel sheet with specific composition through a continuous annealing line fitted with insulating film device. CONSTITUTION:A silicon steel which has a composition consisting of, by weight, <=0.01% C, 0.1-1.6% Si, <=0.7% Mn, <=0.12% P, <=0.01% S, <=0.4% Al, and the balance iron and satisfying Si+Al<=2 is used. This steel is hot-rolled and cold- rolled and the resulting steel sheet is continuously annealed and temper-rolled. After annealing is done at 300-450 deg.C for 5-180sec in continuous annealing equipment fitted with an insulating film device, an insulating film is formed on the surface of the steel sheet. When annealing temp. exceeds the upper limit final magnetic properties are deteriorated, and, when it is below the lower limit, the number of chances to charge is reduced owing to the restrictions on the manufacturing process and productivity is decreased. |
