The influence of microstructural features of individual grains on texture formation by strain-induced boundary migration in non-oriented electrical steels

In order to elucidate the predominance of near-Goss grains after Strain-Induced Boundary Migration (SIBM) in electrical steel sheets, the microstructures of grains of orientations close to Goss, D-Cube, and {111}〈112〉 were observed by TEM after temper rolling of 5 % (which is the optimal strain for the development of a strong Goss-type texture) and 9 % reduction (selected to emphasize the differences between orientations and facilitate their analysis). After 5 % strain, the dislocation density seems to be the smallest in the Goss grains. After 9 % strain, this difference in dislocation density is still present but also accompanied by a difference in dislocation arrangement between the Goss grains and the others. These microstructural features are put in regards to some calculations of rotation rates of individual orientations and analyses of slip system activities performed with the Taylor model. The analysis of all these data allow us to establish a strong link between dislocation microstructure and stability of orientation and to conclude that this correlation may be responsible for the favored growth of the near-Goss grains by SIBM during annealing after 5 % temper rolling.