Comparison of Uniaxial and Rotational Magnetostriction of Nonoriented and Grain-oriented Electrical Steel

Surface domain patterns in electrical steel, which appear under rotational magnetisation, were noted to be comparable to those which are observed under high compressive stress. This paper presents comparison of peak to peak magnetostriction of Epstein strips under high compression magnetised along rolling and transverse directions, and disc samples under rotational and uniaxial magnetisation with no external stress applied. Good correlation was found between magnetostriction measurement results obtained in the rolling direction of non-oriented Epstein strips under high compression and disc samples under rotational magnetisation. Also it was observed that the rotational magnetostriction of grain-oriented electrical steel is greater than its uniaxial value under compressive stress.