Opposite Relationship between Orientation Selection and Texture Memory in the Deformed Electrical Steel Sheets during α→γ→α Transformation

The undesired {111} texture component for the magnetic properties mainly exists in the sheets of electrical steels by the conventional process, whereas the sheets with the non-{111} texture can be obtained by α→γ→α transformation. In this paper, we mainly investigate the opposite relationship between orientation selection and texture memory in the deformed ultra-low carbon steel sheet during α→γ→α transformation annealing. A 0.5 mm thick hot-rolled sheet is directly subjected to transformation. The result shows that the specific transformation textures are not possible to generate in the sheets without deformation. Besides, transformation annealing is conducted on the recrystallized sheets in hydrogen and vacuum, respectively. The near {100} and {110} grains have the growth advantage at the atmosphere/metal interface, and the initial ferrite textures are retained in vacuum. Cold-rolled sheets with different thicknesses are annealed for transformation in vacuum, hydrogen and nitrogen, respectively. The near {100} and {110} textures are still the preferential orientations at the atmosphere/metal interface. When the surface grains have sufficiently large growth advantage, the {111} grains developed by texture memory effect will be annexed. Otherwise, the {111} grains at the center layer of the sheets are hard to be replaced, and they are retained after α→γ→α transformation cycle. The results of deformed sheets annealed with different heating rates in hydrogen show that the growth of initial recrystallization grains has a great effect on variant selection.