RELATION BETWEEN MAGNETOSTRICTION AND MAGNETIC DOMAINS IN CHANGING DIRECTION OF GRAIN-ORIENTED SILICON STEEL SHEET

Research has been carried out on the magnetostriction measured in chan ging direction of grain oriented silicon steel sheets. When the magnet ic field is applied in a direction of 45 degrees off the rolling direc tion normally parallel to Goss texture orientation, the magnetostricti on indicated negative value regardless of compressive stress applied t o specimen and showed favourably smaller negative value in poor coatin g stress condition rather than in good one, which had not been easily imagined by the experience concerning to the magnetostriction in the r olling direction. This was explained by a fact that the 90 degrees sup plementary domains by compressive applied stress followed by the strai n elastic energy theory, which cause positive magnetostriction when th e specimen is exposed to magnetic field, is compensated by negative ma gnetostriction by the abnormal supplementary domains newly generated u nder magnetic field. The abnormal supplementary domain occurs in speci men with the angle to the rolling direction of about 30 degrees-60 deg rees, which was tried to explain by magnetic domain energy. When the m agnetic field is applied in a direction of 90 degrees off the rolling direction, the magnetostriction indicated the largest positive value w hich had been easily supposed by the reaction of the 180 degrees main domain exposed to magnetic field transversely.