Effect of Se Addition on Primary and Secondary Recrystallization in Inhibitor‐Acquired Grain Oriented Silicon Steel

The effect of Se addition on primary recrystallized grain size and texture, inhibitor behavior, secondary recrystallization (SR), and the resultant magnetic properties is systematically investigated in inhibitor‐acquired grain‐oriented silicon steel (GOSS). Compared with Se‐free GOSS, the addition of 0.02 wt% Se refines the primary recrystallized grains and promotes the precipitation of more Mn(S,Se) inhibitors before primary annealing. These inhibitors provide nucleation sites for nitride formation during nitriding, leading to fewer coarse rod‐like composite precipitates and a greater number of finer inhibitors. As a result, the Se‐containing steel exhibits a much finer recrystallized grain size after primary annealing at 800 °C and a lower SR‐starting temperature. However, the magnetic permeability is deteriorated due to the presence of many non‐Goss grains. When the Se‐added and Se‐free GOSSs are primarily annealed at 850 °C and 800 °C, respectively, to obtain comparable grain sizes, the Se‐added steel shows a higher SR‐starting temperature because of the larger number of finer inhibitors. This condition favors the growth of sharp Goss grains and ultimately leads to superior magnetic properties compared with the Se‐free GOSS.