Evolution of recrystallization microstructure and mechanical properties of 3.3%Si high strength non-orientation silicon steel

We investigate the evolution of recrystallization structure and texture of 3.3%Si high-strength non-oriented silicon steel and its effect on magnetic and mechanical properties in this work. The recrystallization structure and texture at different stages of cold rolling and annealing were analyzed by optical microscopy and scanning electron microscopy. The iron loss and magnetic induction intensity were measured by a magnetic energy equipment,and the mechanical properties were measured by a universal tensile testing machine. The results showed the microstructure of 3.3%Si high-strength non-oriented silicon steel is of a fibrous distribution along the rolling direction with main texture being 001< 110> . Partial recrystallization occurs when annealed for 30 s at 900℃.The fibrous microstructure disappears as the annealing time extends,and equi-ferrite was obtained. The grain size increased from 7.8 μm to 25.1 μm. The 111< 112> and 111< 110> textures gradually strengthen. The 114< 481> texture formed when the annealing time is 240 s,which could inhibit the γ texture. The experimental steel achieves optimal magnetic properties and mechanical properties after annealing at 900℃ for 120 s,with a yield strength of 527 MPa,high frequency iron loss P_1.0/400 of 18.79 W/kg,and magnetic induction intensity B₅₀₀₀ of 1.644 T.