Transformation of {100} texture induced by surface effect in ultra-low carbon electrical steel

The {100} texture can appear in different types of electrical steels by means of α → γ → α transformation, and {100} or {110} texture in commercial electrical steels is optimized mainly by deformation and recrystallization. This study investigates the influence of cold rolling on α → γ → α transformation in Fe–0.5 %Mn electrical steels and the possibility of obtaining three types of {100} transformation textures under different rolling reductions. Recrystallization and transformation annealing were conducted on cold-rolled sheets. Results showed that three types of {100} transformation textures were formed, which were closely associated with recrystallization textures. The relationship between these textures can be attributed to texture inheritance. Moreover, hot-rolled and recrystallized sheets were also subjected to transformation, in which two layers of columnar grains without strong {100} texture that impinged at the center of sheet thickness were obtained. Thus, recrystallization and grain growth can enhance the sharpness of transformation texture during the rapid recrystallization process, which occurs before transformation in the cold-rolled sheets by inducing new control factors of variant selection. The rolling plane of cold-rolled sheet heated at 1000 °C for 15 s showed that the {100} transformation nuclei originated from the surface of cold-rolled sheets produced by inhomogeneous deformation.