Primary recrystallization characteristics and magnetic properties improvement of high permeability grain-oriented silicon steel by trace Cr addition

The effect of adding of 0.13 wt% Cr on the primary recrystallization and magnetic properties of high permeability grain oriented silicon steel was studied. The results show that trace Cr refined both primary and secondary grains. The reduction of final grain size resulted in decrease of 5.1%, 4.0% and 3.6% in the average of iron loss during magnetization at 50 Hz, 100 Hz and 200 Hz, respectively. Besides the conventional precipitates, there were two kinds of Cr-containing nitrides, i.e., the amorphous (Si, Cr) N formed in the matrix, and the crystalline fcc-CrN formed at grain boundary. These precipitates acted as inhibitors to refine and homogenize primary grains in the thickness direction. The beneficial {1 1 1} <1 1 2> texture component increased, while the components that cannot form high-energy grain boundaries with Goss grains, such as {0 0 1} <1 1 0> and {1 1 2} <1 1 0> at different thickness layers decreased after primary recrystallization.