Texture Evolution of a 2.8 Wt Pct Si Non-oriented Electrical Steel and the Elimination of the 〈111〉//ND Texture

Abstract

A 2.8 wt pct Si non-oriented electrical steel was thermomechanically processed using conventional hot rolling, hot band annealing, cold rolling and final annealing routes. The evolution of texture during these processes was investigated using electron backscatter diffraction (EBSD) techniques. The final annealing was conducted at 750 °C for various times (10 to 120 minutes), and it was found that by simply changing the annealing time, the texture shows significantly different features, i.e. depending on the annealing time, the Goss ({011}〈100〉), the θ-fiber (〈001〉//normal direction, ND) or the γ-fiber (〈111〉//ND) may dominate the texture. Annealing for 60 or 90 minutes can essentially eliminate the magnetically unfavorable 〈111〉//ND texture while promoting the desired 〈001〉//ND texture. On the other hand, annealing at the same temperature for 30 or 120 minutes, the 〈111〉//ND texture is strengthened and the favorable 〈001〉//ND texture is weakened. The formation of the typical textures observed in each process was examined with respect to known mechanisms existing in the literature. The formation of the various textures during annealing at different times was discussed against the oriented growth theory based on a statistic analysis of the grain boundary misorientation and grain size. It is seen that during annealing at different times, the grain boundary character (e.g. mobility) and the grain size may determine the growth of certain orientations, which give rise to the different textures after annealing for different times.