Effect of Ball Scribing on Iron Loss of CGO and HGO Electrical Steel

The effect of ball scribing on iron loss of conventional grain-oriented （ CGO） and high-permeability grain-oriented （ HGO） electrical steel was investigated. In this paper,ball scribing was achieved by self- designed ball scribing instrument and a computer-controlled system capable of providing high accuracy and automatic measurements was developed for the magnetisation and measurement at high and low flux densities. The results showed that after ball scribing,iron loss of two types of steel （ C711 and H668 ） apparently decreases （ 5. 5% and 8. 2% respectively after 16mm scribing at 1. 2T） ,and at high and low flux densities, CGO and HGO electrical steel performs differently. Through the formation and development of free magnetic poles and secondary magnetic domains due to compressive stress,primary magnetic domain spacing of grain- oriented electrical steel becomes smaller,which reflects as a reduction of iron loss in the macroscopic magnetic properties. Through iron loss formula derivation,the effect of domain refinement on grain-oriented electrical steel was also interpreted.