Smelting and Rolling

Silicon steel is mainly treated with oxygen converter (or electric arc furnace smelting), combined with vacuum treatment of molten steel and AOD technology (see refining outside the furnace, using mold casting or continuous casting method. According to different purposes, the silicon (0.5-45%) and aluminum (0.2-0.5%) contents are changed during smelting to meet different magnetic requirements. The silicon and aluminum content of high-grade silicon steel sheets correspondingly increases. Minimize carbon, sulfur, and inclusions.
Cold rolled silicon steel sheets have better magnetic properties, surface quality, filling coefficient, and punching properties than hot-rolled silicon steel sheets, and can be produced in coils. Therefore, some countries have stopped producing hot-rolled silicon steel sheets since 1960. China adopts the method of rapid hot rolling at a low temperature of about 900 and stacking annealing under hydrogen protection to manufacture hot-rolled silicon steel sheets, with high yield and good surface quality and magnetism of the finished products.