Effect of Cold Rolling Method and Annealing Temperature on Microstructure, Texture and Magnetic Properties of Non-oriented Silicon Steel

Taking continuous and reversible cold-rolled non-oriented silicon steel as the research object, annealing experiments were conducted on it. Metallographic microscope and X ray diffraction diffractometer (XRD) were used to characterize and analyze the microstructure and texture of non-oriented silicon steel with different cold-rolled methods at different annealing temperatures (920–1 070 ℃), and the influence of rolling method and annealing temperature on the magnetic properties of non-oriented silicon steel was explored. The results show that after annealing at 920–1 070 ℃, the average grain size of continuous cold-rolled sample is in the range of 20.7–134.4 μm, and the average grain size of reversible cold-rolled sample is in the range of 17.3–155.5 μm. On the whole, as the annealing temperature increases, the grain size of the annealed plate of both cold rolling methods continues to grow. The texture of cold-rolled plate is mainly composed of strong rotating cubic texture, while the textures of annealing plates of reversible and continuous cold-rolled samples are mainly composed of γ fiber and α fiber textures, and γ fiber texture mainly gathers at 111<112>, α fiber texture mainly gathers at 111<110>. The texture strength of γ fiber decreases significantly with the increase of annealing temperature, and the strength changes of α fiber and Goss and rotating cubic textures are very small.The texture strength of the reversible cold-rolled plate 111<110> is similar to that of the continuous cold-rolled plate. The texture strength of the reversible cold-rolled annealed plate 111<112> is always higher than that of the continuous cold-rolled annealed plate. When annealing at 1 040 ℃, the P_1.5/50 (loss at a magnetic induction intensity of 1.5 T at 50 Hz) of reversible and continuous cold-rolled annealed plates are both the lowest, with values of 2.512, 2.445 W/kg, respectively. When annealing at 1 070 ℃, the P_1.5/50 of reversible and continuous cold-rolled annealed plates increases, and the final values are 2.625 and 2.494 W/kg, respectively.With the increase of annealing temperature, the P_1.5/50 of both cold-rolled annealed plates decreases first and then increases, and the P_1.5/50 of continuous cold-rolled annealed plate is always lower, and B₅₀ (the magnetic induction intensity at a magnetic field intensity of 5 000 A/m) is higher.