Effect of strain rate history on the piezomagnetic field of ferromagnetic steels

Abstract The goal of this research is to investigate the effect of strain rate history on the piezomagnetic behavior of ferromagnetic steels. Cyclic tensile tests were carried out to record the magnetic fields on the surfaces of Q345 and X80 steel specimens. The impacts of different strain rate histories on the magnetic signals were investigated and the evolutions of piezomagnetic fields of Q345 and X80 steels are closely related to the strain rate history. The magnetic fields demonstrate a systematic evolution when the strain rate history increases from 0.03 min-1 to 0.3 min-1. When the strain rate history decreases from 0.3 min-1 to 0.03 min-1, the magnetic fields remain relatively stable. The results were explained by the movement of magnetic domains and the strength of pinning sites induced by the external stress. This study shows that strain rate history should be considered as one of the variables that influence the piezomagnetic field of ferromagnetic steels.