| 摘要 |
PURPOSE:To provide a grain-oriented silicon steel sheet extremely low in core loss by simultaneously executing mirror finishing and secondary recrystallization for a steel sheet in a finish annealing furnace. CONSTITUTION:A hot rolled silicon steel strip is subjected to cold rolling for one time ark two times including process annealing to regulate its sheet thickness into a specified one, and thereafter, primary recrystallization annealing is executed. After that, an oxidizing layer on the surface of the steel sheet is removed away into <=0.3g/m<2> per side of the steel sheet, which is coated with a separating agent for annealing essentially consisting of one or >=two kinds among alumina, silica, zirconia, baryta, strontium oxide and forsterite, and finish annealing is executed. The surface of the steel sheet after the finish annealing has a mirror finished face and high in magnetic flux density. This is subjected to laser treatment and applied with a tension film to obtain ultralow core loss. In this way, the mirror finished grain oriented silicon steel sheet having high magnetic flux density can be obtd. |
