Role of subsurface Goss-oriented grains in abnormal grain growth in Fe-3% Si steel

Abstract

In this study, the differences in the crystallographic orientation, grain size, and grain boundary characteristic distribution along the sheet thickness in Si steel sheets were investigated in order to evaluate preferential sites for the abnormal grain growth of Goss-oriented grains. The grains having exact Goss orientation in the subsurface region of the primary recrystallized Si steel sheets had larger grain size, higher fraction, and higher frequencies of HEGBs and Σ9 GBs, which are claimed to be beneficial to the occurrence of the abnormal grain growth than the grains in the central region. On the other hand, the grains having deviated Goss orientation in the central region had larger grain size and higher Σ9 GBs than the grains having same orientation in the subsurface region. Therefore, it is considered that the high Goss selectivity is peculiar to the position of the nuclei and the beneficial conditions for the abnormal grain growth of exact Goss-orientated grains in the subsurface region.