Abstract: The differences of the secondary recrystallization behavior of 0.20 mm thick grain-oriented silicon steel at different isothermal temperatures and different heating rates were researched in this paper, focusing on the difference of the orientation of secondary recrystallization grains at different temperatures. The microstructures of the TG-CRGO were investigated by electron back-scattered diffraction in this study. The percentage of secondary recrystallization, the change of matrix grain sizes and orientations, and the relationship between the deviation of secondary recrystallized grain orientation to Goss orientation and its grain size were determined. The results showed that increasing the heating rate would delay the start time of secondary recrystallization and slow down the progress of secondary recrystallization; increasing the isothermal annealing temperature would promote the inhibitor ripening and accelerate the progress of secondary recrystallization. In addition, the matrix grains with {114} 〈481〉 orientation were observed to have a significant hindering effect on the growth of secondary grains due to its growth advantage.  Low heating rate and low isothermal annealing temperature (1 030 ℃) were favorable to the formation of sharp Goss texture in the progress of secondary recrystallization. As at this condition, the larger the size of secondary grains, the lower deviation angle to Goss orientation is. 

Key words: isothermal annealing, secondary recrystallization, thingauged grainoriented silicon steel, grain size, texture, deviation angle