Effect of Ball Scribing on Magnetic Barkhausen Noise of Grain-oriented Electrical Steel

Effect of ball scribing on magnetic Barkhausen noise (MBN) of conventional grain-oriented (CGO) and high-permeability grain-oriented (HGO) electrical steel was investigated. The results showed that after ball scribing, root mean square of MBN (MBNrms) of CGO electrical steel increased 9.8% with 4 mm scribing spacing at 1.2 T, and that of HGO electrical steel apparently decreased 17.3% with 16 mm scribing spacing at 1.2 T. Through the formation and development of free magnetic poles and secondary magnetic domains due to compressive stress, primary magnetic domain space of grain-oriented electrical steel becomes smaller, which reflects as a variation of MBN in the macroscopic magnetic properties. Through correlation formula derivation of MBNrms and equilibrium distance between domain walls, effect of domain refinement on grain-oriented electrical steel was also interpreted, and optimum equilibrium distance between domain walls was determined.