2014 年 22 巻 2 号 p. 163-169
Magneto-Acoustic Emission (MAE) is stress pulses observed during dynamic magnetization process of ferromagnetic material. The abrupt and discontinuous motion of 90° magnetic domain wall and rotation of local magnetization are considered as the major MAE sources. The characteristics of MAE depend on the applied stress because the stress influences the structure of magnetic domain. On the other hand, the MAE incidence is expected to be proportional to the magnetized volume in which the 90° domain wall motion and rotation of local magnetization occur. For actual engineering applications, it is important to clarify the correlation among the applied stress, the magnetized volume and the generated MAE. In this paper, we focus on the dependence of the MAE incidence on magnetization rate and examine the correlation for SM490A steel under several tensile stresses.