Effect of Cut-Edge Residual Stress on Magnetic Properties in Non-Oriented Electrical Steel

The non-oriented electrical steels are widely used as motor core materials after the punching process. During the punching process, residual stress is inevitably generated at cut-edge; therefore, magnetic properties are deteriorated. In this paper, the effect of cut-edge residual stress on magnetic properties was investigated. The samples were cut by various methods to induce different amounts of residual stresses at cut-edges. The residual stress was analyzed by optical microscopy, micro Vickers hardness tester, and electron backscatter diffraction. The magnetic properties in low-field strength were closely related to residual stress, because the magnetic domain wall motion is inhibited by crystal lattice defects.