Influence of stress relief annealing temperature on the cutting edge microstructure and on the recovery of magnetic properties of grain oriented electrical steel

Abstract

The effect of stress relief annealing temperature on the recovery of the magnetic properties deteriorated by strain and stresses introduced by shear cutting was analyzed in this study. Shear cut Epstein samples of grain oriented electrical steel were submitted to heat treatment at different annealing temperatures (600–900 °C). The magnetic properties were measured before and after annealing. The microstructures of the sheared edges before and after annealing were characterized using scanning electron microscope (SEM) equipped with electron backscattered diffraction (EBSD) in which it was possible to characterize the recovery and recrystallization processes responsible for the stored energy release in the shear cut region. The magnetic properties were improved with the increase of the annealing temperature due to recovery, recrystallization and the relief of residual stresses.