Effect of Rare Earth Element La on Texture and Inclusion of Non-oriented Electrical Steel Produced by Thin Slab Casting and Rolling Process

Effect of rare earth element La on non-oriented electrical steel produced by thin slab casting and rolling process is investigated by using transmission electron microscope, scanning electron microscope and X-ray diffraction. The results show that, (1) The columnar crystals are refined obviously with the addition of rare earth element La, the primary dendrite arm spacing is reduced from 2.42 mm to 1.76 mm, and the secondary dendrite arm spacing is reduced from 0.35 mm to 0.28 mm. (2) The banded structure of the hot rolled plate in center is significantly improved after adding rare earth, the thickness of the banded structure is reduced from 0.75 mm to 0.24 mm. (3) With the addition of rare earth element La, the precipitation morphology of AIN transforms from lump to spherical, the density and amount of inclusions are greatly reduced. (4) The average grain size of finished product is increased with the addition of rare earth element La, meanwhile, the unfavorable texture of (111) decreases and the favorable texture of (100) and (110) increases. With the addition of rare earth, the average core loss is decreased by 0.4 W/kg, and the average magnetic induction intensity is increased by 0.011T.