Core loss reduction in grain oriented silicon steel sheets by two-sided laser scribing in the presence of a magnetic field

Abstract An approach to decrease the core (iron) loss of grain-oriented silicon steel sheets is to reduce the magnetic domain size by using laser irradiation on the surface of the sheets. In this research, after finding the optimal conditions for traditional laser scribing of HIB (high-permeability)-steel sheets, the effect of the two new parameters "two-sided laser-scribing" and "simultaneous application of magnetic field during laser-radiation" on reducing core losses was investigated. By optimizing the variables in the traditional method (laser scribing on one side without the presence of magnetic fields), core losses at 1.7 T and 50 Hz were reduced by 9.7%. Laser treatment of both sides resulted in a decrease of core loss of 13.7%. Applying a magnetic field during laser scribing could have a positive or negative effect on core losses, depending on the direction of the magnetic field. In the optimum conditions, with double-sided laser scribing of HIB-sheets in the presence of a magnetic field, core losses were reduced by 16.8%. This is a significant result compared to the 9.7% of the traditional method.