Warm rolling combined with rare earth yttrium segregation induces secondary recrystallization in strip-cast Fe-3%Si grain-oriented silicon steel

The effect of warm-rolling on the microstructure, texture, and magnetic properties of ultra-low carbon yttrium (Y) -doped grain-oriented (Y-GO) Fe-3%Si steel as-cast strips were systematically investigated. Rare-earth Y atoms interact with dislocation-solute complexes to induce dynamic strain aging (DSA), which effectively promotes the formation of various shear bands during warm-rolling at 450 °C. Intensive and coarse shear bands were found in the warm-rolled specimens, providing additional nucleation sites for recrystallization. Meanwhile, the reduction in critical shear stress during warm rolling activates more slip systems, facilitates uniform deformation, and ultimately weakens the texture intensity. The grain size of the intermediate-annealed and primary-annealed specimens after warm rolling was significantly refined, indicating that the improved microstructure enhances secondary recrystallization. These results suggest that an optimal microstructure and texture in strip-cast yttrium-doped Fe-3%Si steel can be achieved through warm rolling, leading to an increase in magnetic induction B8 from 1.71 T to 1.81 T.