| To investigate the effect of the microstructure prior to high temperature annealing on the secondary recrystallization in grain oriented electrical steels, the specimens, containing 3.1%Si, 0.034%C, 0.017%Al, 0.008%N, were annealed at 400, 600 and 850℃ for 5 min, in 10% N2+90%H2 atmosphere after the second stage cold rolling and then together with as-rolled specimens, heat-treated again for secondary recrystallization. It has been found that having a fully recrystallized matrix prior to high temperature annealing is not a precondition for complete development of the secondary recrystallization. As the microstructure prior to the final annealing changed from a fully recrystallized to an as-rolled state, the sizes of the secondary grains became larger and their formation temperature higher due to the differences in the microstructures and textures during the heating stage of the final annealing. The specimens with as-rolled and recovered matrices showed better magnetic induction values than the fully recrystallized, of which implication was more ideal orientation of the secondary grains. |
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