Stability of residual magnetized state of tool steels

Magnetoelastic sensitivity of 30Kh18, 40Kh, ShKh15, R18, R6M5, R9K5 steels was studied. Samples in cylindrical form were subjected to thermal treatment (annealing, quenching and tempering)> Initial magnetic state of samples was achieved through their magnetization in electromagnetic field up to their saturation. Sample loading (compression) was carried out on hydraulic press. The order of sample measurement was as follows: magnetization, measurement of initial value if residual magnetized sate, placing sample in cartridge, loading and measurement of final value of residual magnetized state. Instability of residual magnetized state of certain tool steels in dependence on the value of compression strains, character of thermal treatment, integration effect by multiple loadings, from demagnetization factor and temperature (from-55 up to 45 deg C) is shown. The obtained data are presented in graphical form. 9 refs., 4 figs