Relation of magnetostriction for cold-rolled transformer steel to shape of specimen and internal stress

Conclusions

• 1. Well-annealed cold-rolled transformer steel has an energy density for the form anisotropy approximately equal to the mean energy density for the internal stresses.

• 2. This feature determines the characteristics of the magnetization in weak fields, for which displacement of 90 ° boundaries is important; phases perpendicular to the field (or nearly so) grow at the expense of ones antiparallel to the field (or nearly so). A certain optimal magnetic texture in the demagnetized state can give rise to negative magnetostriction in weak fields.

• 3. The magnetostriction constants must be determined with allowance for the shape of the specimen, the orientation of the crystal relative to the plane of the specimen, and the internal stresses; a correct result will not be obtained unless either there is no magnetic texture in the demagnetized state or correction is made for that texture. It is incorrect to say [8] that the magnetostriction constants are not universal.