Influence of the plastic anisotropy on the magnetic properties of a nonoriented 3% silicon iron

Abstract

Modifications of the magnetic properties of a nonoriented 3% SiFe alloy with plastic strains are reported. The samples have been tested along rolling and transverse directions lying in the sheet plane by means of a suitable experimental system of measurements using a 50 Hz sinusoidal magnetic field. The magnetic properties markedly deteriorate when measurements are carried out in the direction of the applied stress. This phenomenon is less important perpendicular to the applied stress. Quasistatic experiments (f=0.1 Hz) have been accomplished to separate the total losses into hysteresis and dynamic components. Hysteresis losses strongly increase and dynamic losses sensitively decrease with the plastic deformation whatever the direction in sheet plane. Compression-tension fatigue tests carried out have shown that the material displays a strong kinematic strengthening behavior representative of internal and long range stresses in the strained sample. The degradation of the magnetic properties of nonoriented 3% SiFe alloys with plastic strains is the result of two effects: one due to dislocations and another due to internal stresses. The latter display along the direction of magnetic measurements the same effects as an outside elastic stress.