Effect of cold-rolling deformation and rare earth yttrium on microstructure and texture of oriented silicon steel

In order to study the effect of cold-rolling deformation and rare earth Y on the microstructure and texture of 3.0% Si-oriented silicon steel, the microstructure and texture of cold-rolled oriented silicon steel with 60, 72, and 86% deformation are analyzed using electron backscatter diffraction and image analysis software. The experimental results show that the deformation band becomes narrower and the distribution of shear bands becomes denser with increasing cold-rolling deformation. Compared to the Y-free steel, cold-rolled sheet containing rare earth Y has greater shear bands. The pinning effect of rare earth Y hinders the dislocation movement, which leads to the increase of kernel average misorientation value and shear bands. With the increase of cold-rolling deformation, the texture concentrates on alpha and lambda. This is mainly due to the change from {100} < 001 > to {001} < 110 >, intensifying lambda texture, and the change from {111} < 112 > to {111} < 110 >, thus strengthening the alpha texture. The texture strength of cold-rolled sheets can be decreased by rare earth Y. But the gamma texture strength in cold-rolled sheets containing Y is significantly higher than in those without Y. The gamma texture strength can reach up to 7.3, and the strong points are mainly {111} < 112 >. This is because the number of inclusions in steel increases with the addition of rare earth Y. In the process of grain nucleation, the {111} oriented grains nucleate heterogeneously on the inclusions. It forms a large number of {111} oriented grains and improves the gamma texture strength.