METHOD FOR TWO-STEP HOT ANNEALING HIGH PERMEABILITY GRAIN ORIENTED SILICON STEEL

摘要

PURPOSE: A method for two-step hot annealing a high permeability grain oriented silicon steel is provided to add excellent magnetic property while lowering the contained amount of C and S. CONSTITUTION: A slab is composed of 2.9-3.5wt% of Si, 0.01-0.07wt% of C, 0.05-0.15wt% of Mn, 0.020-0.035wt% of Sol-Al, 0.01-0.025wt% of S, 0.1-0.2wt% of Cu, and the remnant wt% of Fe and impurities. The slab is heated at a temperature of under 1360°C for hot rolled to be a hot rolled sheet. The hot rolled sheet is annealed at a temperature of 950-1150°C for being decarbonizing annealed and hot annealed. Herein, the hot annealing is formed by raising the temperature at a speed of 18-30°C/h in the temperature range of 700-1050°C and by raising the temperature at the speed of 10-15°C/h in the temperature range of 1050-1200°C.