IDENTIFICATION OF MICROSTRUCTURE EFFECTS IN MAGNETIC LOSS BEHAVIOR OF3.2-PERCENT SIFE N.O. ELECTRICAL STEELS BY MEANS OF STATISTICAL POWERLOSS MODEL

In this work systematic experiments were carried out to attempt the id entification of microstructural effects (texture, grain size) on the p olarization dependence of internal coercive field V-o and hysteresis l oss P-hys, determined by statistical power loss model (SPLM). Experime nts were performed on 0.35mm thick 3.2wt% SiFe non-oriented electrical steel, with different grain size and almost the same crystallographic texture. From each material Epstein samples were cut at different ang les to the rolling direction (RD). Loss separation and fitting process was carried out, according to the SPLM, for determining V-o and P-hys as a function of the polarization. Three synthetic parameters were pr oposed in the 0.3T-1.2T polarization range, where the model was found to be valid: two coefficients P-(hys)(o) and n(1) to represent the hys teresis loss according to an exponential law and an average value of t he internal coercive field V-o((avg)) over the investigated polarizati on range. The dependence of V-o((avg)), P-(hys)(o) and n(1) on the gra in size and texture has been clearly identified, resulting in a single texture dependent behavior for both quasistatic and dynamic propertie s. All the results obtained from fitted Phys values were confirmed by quasi-static measurements. A theoretical model, based on the measured Orientation Distribution Function (ODF) has been proposed to reproduce the obtained texture dependence.