Investigation on the Microstructure and Texture Changes of 2% Si Non-oriented Silicon Steel under Different Processes
摘要
For the 2% Si non-oriented electrical steel (a critical silicon grade), three processing routes were comparatively investigated: single-stage cold-rolling process, normalization + single-stage cold-rolling process and two-stage cold rolling with intermediate annealing process. EBSD analysis revealed that the hot-rolled plate exhibited shear texture {110} <115> in surface layers and rolling texture {113} <110> in the center layer. The single-stage cold-rolled specimen developed strong α-fiber texture with weak γ-fiber components. After annealing, the dominant texture components comprised intense α*-fiber accompanied by relatively weaker λ-fiber and γ-fiber textures. The normalization + cold-rolling process produced annealed plates with predominant α*-fiber texture and suppressed γ-fiber formation, resulting in the largest final grain size among all processes. The two-stage cold rolling with intermediate annealing yielded a strong λ-fiber dominated texture. This process achieved optimal magnetic properties: minimum iron loss P1.5/50 of 2.778W/kg and maximum magnetic induction B50 of 1.765 T. Normalization significantly promotes grain growth, but the relationship between grain size and iron loss is not monotonically decreasing. The two-stage rolling with intermediate annealing effectively eliminates detrimental γ and α* texture components while enhancing λ-oriented grains, leading to remarkable magnetic property improvement.