The influence of cooling rate on microstructure and magnetic properties of cast Fe-6.5wt%Si steel

Abstract

Abstract Fe-6.5wt%Si steel samples of different thicknesses (1 mm, 2 mm, and 5 mm) were prepared by arc-melting and suction-casting with sub-rapid solidification rates. The microstructures and magnetic properties of the samples were studied, and the effect of solidification rates were discussed. Results show that columnar crystals are generated with a <100> fiber texture after casting. Ordered phases B2 and D03 are inhibited by sub-rapid solidification, and such an effect is clear in the 1 mm thick sample with the largest cooling rate. With decreasing cooling rate, the grain size increases, with the mean values being 66.6±30.8 μm, 93.0±42.8 μm, and 149.7±66.8 μm, and the intensity of the <100> texture increases, with the values being 3.14 mrd, 3.56 mrd, and 5.85 mrd, respectively. The 5 mm thick sample with the lowest cooling rate exhibits the best magnetic properties (B8=1.30 T, B50=1.55 T, P1/50=2.19 W/kg, P1/400=37.85 W/kg).