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In this paper, we use a phenomenological model based on the Jiles-Atherton-Sablik model of stress affecting the magnetic hysteresis of magnetic materials as modified when stress goes past the yield stress We use this to show that (1) the model produces sharp shearing of hysteresis curves, as seen experimentally and that (2) it also produces a step in the hysteresis loss at small residual plastic strain. We also find that the step in the hysteresis loss can be fitted to a power law, and find that the power law can be fitted by the power m=0.270, different from the mechanical Ludwik Law exponent, and reasonably close to the experimental 0.333 and 0.202. We will also suggest a method of measuring how plastically deformedthe material is by suggesting how the dislocation density can be measured. more...

Application of the Sablik-Jiles magnetomechanical theory to various NDE techniques for measuring stress in steels is reviewed. Among the techniques discussed are (1) differential anhysteretic susceptibility, (2) higher order harmonic amplitudes of the hysteretic magnetic flux density, (3) magabsorption, which involves measurement of the rf impedance of a coil coupled to a ferromagnetic material, and (4) Barkhausen measurements. more...

Changes in the magnetic properties of a cruciform-shaped SAE-4130 steel specimen were measured under biaxial stress conditions. Compared to model predictions are the experimental remanence at various biaxial stresses and the magnetically induced velocity changes (MIVC) of ultrasonic shear and longitudinal waves propagated perpendicular to the stress plane. more...

A spin system, with spins which tend to align perpendicularly in the xor ydirection, is studied via Monte Carlo simulation using the Metropolis algorithm. Spins are allowed to have six projections - up (+z), down (−z), right (+x), left (−x), front (+y), and back (−y) - just as in the ‘cubic model’. Specific heat, magnetic susceptibility, and magnetization are sampled in the presence of a magnetic field with equal xand ycomponents. Spins on both simple cubic and face-centered cubic lattices are studied. Results are compared to the results for the cubic model. more...