Magnetic Properties and the Structure of Eutectoid Steel with Different Pearlite Morphology

Abstract—It is shown that the size and shape of cementite inclusions in eutectoid steel determine its magnetic properties in both unstrained and plastically strained states. In the case of the unstrained state, the coercivity of steel comprising a fine pearlite is found to be the highest, whereas the coercivity of steel comprising a coarse pearlite is the lowest. Tensile plastic deformation leads to an increase in the coercivity of samples and a decrease in their remanence and maximum magnetic susceptibility. The appearance of bend or a second maximum in the field dependences of the magnetic susceptibility measured along the deformation direction indicates the formation of the “easy-plane” magnetic texture caused by residual compressive stresses. Calculated magnetic anisotropy fields of initial unstrained samples of eutectoid steel differing in pearlite morphology are from 10.4 to 19.1 A/cm. The plastically strained samples exhibit an increase in the induced magnetic anisotropy and, therefore, in the residual stresses as compared to those observed for the unstrained state.