Effect of Refined Surface Domains Walls on the Core Losses Components in GO Silicon Steel at Different Frequencies

The fiber laser scribing was performed on the surface of grain-oriented (GO) electrical steel, in order to investigate the influence of surface magnetic domains modification on its magnetic losses components.The domains refinement was carried out by the laser beam in continuous regime with the power up to 30 W, and two constant distances between the neighbouring scribing lines, respectively, 4 mm and 10 mm.It was shown that laser radiation induces the thermal residual stresses at the area of interaction with steel surface that allow to effectively refined surface domain structures, and decrease the hysteresis losses and excess losses of treated steel.The total losses and its components on samples treated by the individual laser scribing regimes were measured in DC and AC magnetic field up to 50 Hz at maximum flux density of 1.5 T. The obtained results clearly show that experimental samples were characterized by significant decrease of hysteresis losses and excess losses after the surface laser processing.