Magnetomechanical effect of low carbon steel studied by two kinds of magnetic minor hysteresis loops

摘要

Two lands of magnetic minor hysteresis loops were simultaneously measured in a low-carbon steel sample under uniaxial tensile stress by using a magnetic probe. For the minor loops measured by the Hall sensor and direct pickup coil, the coercivity H_C and hysteresis loss W_H showed a sudden increase at an applied field H_a above 3 kA/m due to the stray flux. As to the other minor loops derived from the calculated H_a and indirect pickup coil, no sudden changes in H_c and W_H took place, and the curves of H_c or W_H vs applied stress almost paralleled with each other with H_a above 2 kA/m. H_c and W_H of these two minor loops obtained at suitable H_a showed similar dependences on the applied stress in both elastic and plastic regions. The clear relationship between magnetic properties and external stress is quite applicable in NDE.