Microstructural evolution and magnetic properties in strip cast non-oriented silicon steel produced by warm rolling

摘要

In this study, a specific warm rolling was implemented to process Fe-2.8%Si steel by novel twin-roll strip casting. The impact of warm deformation on mechanical behavior, microstructural evolution and magnetic properties is presented. The study indicated that dynamic strain aging (DSA) occurred in the temperature range of 150-300 degrees C. The elevated rolling temperature strengthened DSA effect and promoted the formation of shear bands. The nucleation process of Cube ({100} < 001 >) grains during annealing was weakened on introducing warm rolling, while that of Goss grains ({110} < 001 >) was enhanced. Moreover, the recrystallization texture pattern of (Cube + Goss) gradually transformed into a pattern of only pronounced Goss texture. The corresponding values of magnetic induction B-50 at rolling direction and transverse direction were obviously improved. This confirms the feasibility of processing ultra-high-permeability non-oriented silicon steel based on twin-roll strip casting combined with DSA-control rolling. However, the rolling process increased the nucleation site for recrystallization and decreased the size of precipitates in annealed sheet, leading to a reduction in grain size and an increase in core loss.