Research on the piezomagnetic hysteresis of ferromagnetic steels under elastic cyclic loadings with variable amplitudes

Abstract

The goal of this research is to investigate the variations of the piezomagnetic hysteresis of ferromagnetic steels under cyclic loadings. A Series of cyclic tensile tests are conducted to measure the piezomagnetic fields in the vicinity of the X80 and Q345 specimens. It is found that the trajectories of piezomagnetic hysteresis curves of different peak stresses overlap in the loading process. The slopes of the unloading piezomagnetic hysteresis curves at the starting and ending points have linear relation with the cyclic peak stress, respectively. The experimental results are analyzed and explained from the perspective of thermodynamics. Combined with the existing theoretical model, the macroscopic factors affecting the piezomagnetic hysteresis curve are discussed. The unloading piezomagnetic hysteresis curve may be a promising piezomagnetic tool for evaluating the mechanical and magnetic properties of ferromagnetic steels.