Modification and experimental study of magnetization model of ferromagnetic materials based on J-A theory

In this paper, a new magnetization model is proposed, aiming at model correction based on the J-A model: a magnetization correction model is established in the elastic and plastic stages, respectively, and the relationship between the magnetization and the external magnetic field, stress and plastic strain is analyzed,and explain the asymmetric phenomena. The experimental results show that when the Q235 steel plate is in the elastic stage, the magnetic memory signal increases with the increase of the stress; when the Q235 steel plate is in the plastic stage, the magnetic memory signal first decreases and then increases with the increase of the stress,and finally tends to be stable; when the Q235 steel plate transitions from the elastic stage to the plastic stage, the magnetic memory signal produces a "cliff" decline, which corresponds to 0.5% plastic strain. This study shows that the novel magnetization model provides a new method for detecting ferromagnetic materials from the elastic stage to the plastic stage.