On the influence of plastic deformations of low-carbon ferromagnetic steels on the changes in the shapes of their hysteresis loops and the field dependences of the differential permeability

摘要

It is shown that inflections in the hysteresis loops of DN,3 low-carbon steel after its plastic deformation are determined by the appearance of a magnetic state of the easy-plane type in a part of the grains. The residual compressive stresses were found at which the maximum possible number of jumps of 90A degrees domain boundaries (DBs) are observed. An expression for the energy of a domain with a 90A degrees DB was obtained. It depends only on the field, the residual stresses, and the angle between the field and the chosen easy axis (EA) of a grain that is located in the easy plane (EP). This made it possible to find the conditions for the onset of irreversible jumps of the 90A degrees DBs to the EP and back. As a result of the proposed theoretical model, the values of the fields of the differential permeability mu (d) (H) peaks were determined, which are observed in positive and negative magnetic fields on the descending hysteresis-loop back. The ratios of the magnitudes of these peak were also found.