Effects of isofield uniaxial cyclic stress on the magnetization of 2% Mn pipeline steel-behavior on near saturation major hysteresis loop

Measurements of the effects of cyclic stress on the magnetization of a sample of 0.08%-C 2%-Mn pipeline steel are presented. The sample was magnetized to a position on the upper branch of the near saturation major hysteresis loop. Cyclic uniaxial tension or compression was then applied to the sample under isofield conditions. Two types of stress cycle were tested, one where the maximum stress applied to the sample increased after every cycle, and one where the maximum stress was held at a constant value for each cycle. Plots of the resulting changes in the magnetization indicated the presence of two types of irreversible behavior produced by the stress cycles-irreversible changes in the unstressed magnetization and stress-magnetization hysteresis. The former behavior was found to fall into three different categories that depended on the magnetization of the sample and the type of applied stress. These categories were analyzed in terms of the expected effects of the different stresses on the different magnetization mechanisms, namely, 180/spl deg/ domain wall motions, 90/spl deg/ domain wall motions, and domain magnetization vector rotations.<
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