The influence of punching and laser cutting technologies on the magnetic properties of non-oriented silicon iron steels

Punching and laser cutting of non-oriented silicon iron sheets (NO FeSi) determine changes in the material at the cutting edge, which produce an important effect on the magnetic properties. Through punching it results a plastic deformation in the zone near the cutting edge. Laser cutting technology causes thermal stresses, which alter also the magnetic properties. The knowledge of the type of deterioration is very important for the production of the electrical machines, because of the increased total losses. There were tested steel samples of NO FeSi grades, M400-65A and M800-65A, with an area of 300 × 30 mm². The magnetic properties were measured with a laboratory single strip tester in the range of frequency from 10 ÷ 400 Hz at 1 T peak magnetic polarization.