Effect of rare earth Y on texture evolution and properties of non-oriented electrical steel

Abstract

This study systematically investigated the microstructure and texture evolution of non-oriented electrical steel with different rare earth yttrium contents during hot rolling, normalizing annealing, cold rolling, and recrystallization annealing. The magnetic and mechanical properties of non-oriented electrical steel with different yttrium contents were measured. The experimental results clearly demonstrated that the role of rare earth yttrium exhibits distinct diversifications at different stages. During the solidification process, the rare-earth yttrium promoted the formation of high-melting-point inclusions, which acted as efficient nucleation sites to improve the ingot microstructure. During rolling and recrystallization annealing, rare earth yttrium coarsened inclusions, reduced pinning effect and nucleation energy, promoted the nucleation of low-energy {100} and {110} grains, and significantly limited the growth of γ-fiber grains. As a result, the magnetic properties of the experimental steel with rare earth yttrium were significantly improved. Rare earth yttrium is not beneficial for the mechanical properties of non-oriented silicon steel, mainly because the addition of rare earth yttrium promotes the precipitation of large particles, resulting in stress concentration during deformation and reducing the mechanical properties of non-oriented silicon steel. Considering both magnetic and mechanical properties, it is recommended to add 0.016% rare earth yttrium for preparing non-oriented electrical steel.