Relation between magnetostriction and magnetic domains in changing direction of grain oriented silicon steel sheet

Abstract

Research has been carried out on the magnetostriction measured in changing direction of grain oriented silicon steel sheets. When the magnetic field is applied in a direction of 45° off the rolling direction normally parallel to Goss texture orientation, the magnetostriction indicated negative value regardless of compressive stress applied to specimen and showed favourably smaller negative value in poor coating stress condition rather than in good one, which had not been easily imagined by the experience concerning to the magnetostriction in the rolling direction. This was explained by a fact that the 90° supplementary domains by compressive applied stress followed by the strain elastic energy theory, which cause positive magnetostriction when the specimen is exposed to magnetic field, is compensated by negative magnetostriction by the abnormal supplementary domains newly generated under magnetic field. The abnormal supplementary domain occurs in specimen with the angle to the rolling direction of about 30°-60°, which was tried to explain by magnetic domain energy. When the magnetic field is applied in a direction of 90° off the rolling direction, the magnetostriction indicated the largest positive value which had been easily supposed by the reaction of the 180° main domain exposed to magnetic field transversely.