Texture and magnetic properties of non-oriented electrical steels processed by an unconventional cold rolling scheme

Abstract

Two non-oriented electrical steels containing 0.9wt% and 2.8wt% of silicon were processed using an unconventional cold rolling scheme, i.e. the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) so that the initial texture before cold rolling and the rotation paths of crystals during cold deformation were both altered as compared to conventional cold rolling along the original HRD. The cold-rolled steel strips were then annealed, skin-pass rolled and final annealed. The texture and microstructure of the materials were characterized by X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and optical microscopy, and considerable differences in average grain size and texture were observed at different inclination angles. The magnetic properties of the steel strips were measured at 400Hz and 1.0T/1.5T using a specially designed Epstein frame, and apparent differences were also noticed at various angles. The magnetic quality of texture was evaluated using different texture factors/parameters and compared to the measured magnetic properties. Although apparent improvement on the magnetic quality of texture can be noted by inclining the CRD to HRD, the trend does not match the measured magnetic properties at 400Hz, which may have been affected by other parameters in addition to crystallographic texture.