Influence of Cutting Techniques on Magnetostriction Under Stress of Grain Oriented Electrical Steel

The magnetostriction of Epstein strips of 0.30 mm thick grain oriented electrical steel cut using three techniques was measured under longitudinal applied stress. Commercially available guillotining, electrical discharge machining, and laser cutting techniques were used. The parameter used to determine their effect was the stress shift of the peak to peak magnetostriction. The increase in the magnetostriction, especially under compressive stress, is related to the appearance of domain stress patterns on the strip surface. Hence, to investigate and correlate the cutting stress with the shift of the curve of magnetostriction against stress, static domain observations were carried out. The results from the magnetostriction under stress measurements show that all utilized cutting techniques set up compressive stress in the strips indicated by a shift of magnetostriction stress sensitivity curves, stress domain patterns on the strips surface, and distortion of B-H loop characteristics.