| 摘要 |
PURPOSE:To form stably a forsterite film on the surface of a grain-oriented silicon steel strip which is cold rolled by grinding the surface of said strip with a specific material then subjecting the strip to decarburization annealing, coating MgO for preventing tight adhesion, coiling the strip and subjecting the coil to finish annealing. CONSTITUTION:The surface of the grain oriented silicon steel strip 11 which is cold rolled by a Sendzimir mill, etc. down to the final sheet thickness is ground with plural pairs of grinding brushes 13 each consisting of a soft non-woven fabric, etc. contg. carborundum or 'Alundum(R)' abrasive grains to remove the oxide such as iron oxide from the surface of the steel strip. The strip is then cleaned with a water spray 14 and is dried in a dryer 15; thereafter, the strip is put into a continuous decarburization annealing furnace 16 where the strip is subjected to the decarburization annealing at 800-850 deg.C to form subscale of SiO2, etc. on the surface. MgO 17 which is the separating agent for annealing to prevent the tight adhesion of the steel strip to each other is coated on the surface thereof in the stage of the finish annealing. The strip is then coiled by a coiler 11 and the coil is subjected to the final annealing at 1,200 deg.C in a finish annealing furnace 19. The forsterite film is formed by SiO2 and MgO, by which the surface roughness, space factor, electromagnetic characteristic and appearance of the steel strip are improved. |
