Effect of Processing Methods on the Magnetic Properties of Non-oriented Electrical Steel

The effects of two sample processing methods, punching and laser cutting, on the magnetic properties of high-grade non-oriented electrical steel were studied. The results show that the coercivity and iron loss of laser cutting samples are higher than those of mechanical punching, while the permeability gets lower in laser cutting samples. Through the analysis of grain internal stress by EBSD, it is found that there is a stress concentration area in the cutting section of punching sample, while there is no obvious stress concentration area near in the cutting section of laser cutting sample. While the laser cutting surface is wrapped with an oxide layer with the thickness of 1 μm through EDS energy spectrum analysis. The oxide layer causes the hysteresis loss increased under the magnetic induction intensity of 1.0 T, and the influence is amplified with the increase of loading frequency. However, when the magnetic induction intensity increases to 1.5 T, the influence of oxide layer on hysteresis loss decreases and the abnormal loss increases.