Magnetic properties measurement and analysis of electrical steel sheet under cutting influence

Abstract

The cutting process of silicon steels is a necessary manufacturing technique in electrical equipment. Different cutting methods have different effects on the internal structure and magnetic properties of the electrical steel sheets. Laser cutting can produce thermal stress during processing, while mechanical cutting may cause plastic deformation near the cutting edge, which both lead to deterioration in the magnetic properties of the material. Therefore, studying the effect of different cutting techniques on magnetic properties is of great significance to accurately predict the iron losses of electrical equipment. In this paper, a mobile B-H sensing structure is designed to sense the distribution of local magnetic properties near the cutting edges. Magnetic properties of the non-oriented (NO) silicon steel samples B35A270 and 50JN470 are measured and characterized with the variation of distance from cutting edges. The results demonstrate that the deterioration of magnetic properties depends on the cutting methods and the material characteristics. Wire cutting has little effect on magnetic performance and the effect can be observed near the cutting edge. As a contrast, the decrease of the relative magnetic permeability can be observed in a deeper width of the steel strips cutting by laser. Moreover, the multiple trends of laser cutting loss which vary with cutting depth are compared and discussed. This research can provide a reference for the application of electrical equipment under actual working conditions.