The effect of direct current in a steel rod on the switching field dependence of magnetic permeability

It is theoretically shown that in cases where the process of irreversible magnetization reversal of ferromagnetic steels is determined by displacements of only 180° domain boundaries, the dependences of reversible permeability on the switching field in low-carbon steels when a direct current is passed along a rod sample should have two maxima instead of the usual one that occurs in the absence of this current. The distances between the maxima of these peaks linearly depend on the value of the constant component of the current and, consequently, on the constant circular magnetic field caused by it, perpendicular to the switching field. This phenomenon should occur both for undeformed steel samples in the state after annealing and for samples after plastic stretching. In the latter case, elastic tensile stresses of such magnitude should act to compensate for internal residual compressive stresses. The fields of both peaks of magnetic permeability in these two cases are close to each other.