Silicon alloy steel with 1.0~4.5% and carbon content less than 0.08% is called silicon Steel. It has the characteristics of high permeability, low coercivity and large resistance coefficient, so the hysteresis loss and eddy current loss are small. It is mainly used as magnetic material in motors, transformers, electrical appliances and electrical instruments. In order to meet the needs of the punching and shearing process, some plasticity is required for the manufacture of electrical appliances. In order to improve the magnetic sensing performance and reduce hysteresis loss, it is required that the lower the harmful impurity content, the better the plate shape, and the better surface quality.