Influence of cooling rate on iron loss behavior in 6.5Â wt% grain-oriented silicon steel

The influence of cooling rate on iron loss behaviors has been investigated in 6.5 wt% grain-oriented silicon steels. To fabricate 6.5 wt% grain-oriented silicon steels and control the microstructure, 3.0 wt% grain-oriented silicon steels covered with SiO2 materials were annealed at 1200 °C and then cooled to room temperature using oil quenching, air cooling, or furnace cooling. The magnetic loss of furnace-cooled samples was reduced by 25% compared with oil-quenched samples due to lower anomalous and hysteresis losses. Microstructural analysis showed that these loss behaviors were strongly related to the formation and growth of ordered phases, i.e., B2 and D03. These correlations could be ascribed to the formation of antiphase boundaries, which acted as pinning sites of the magnetic domain walls.