Effect of rare-earth yttrium doping on the microstructure and texture of hot-rolled non-oriented electrical steel

This study draws on the conventional non-oriented electrical steel (NOES) composition, with different contents of the rare earth element Y, and studies the effects of the rare earth Y on the microstructure and texture of NOES ingots and hot-rolled plates. The results indicate that rare earth Y can purify the melt, form high-melting second-phase particles, and significantly refine the ingot microstructure during the solidification process with pinning action. The effect of rare earth on the hot-rolled plate microstructure exhibits an inverse “structural heredity effect.” The coarse ingot microstructure without rare earth forms a fine gradient organization after hot rolling, with the surface and sub-surface being dynamic recrystallization microstructures, the center layer being a deformation microstructure, and the sub-surface forming a sharp shear brass texture. The fine ingot microstructure formed by adding a rare earth becomes relatively coarse and uniform after hot rolling. An appropriate amount of rare earth Y can significantly pin the brass-oriented grain boundaries, inhibit the development of brass components, and enhance the {100} and its variant hot-rolled textures. Considering the grain size and texture of the hot-rolled plate, it is recommended to add 0.012%Y to prepare NOES.