Effect of Annealing Temperature on the Texture and Magnetic Barkhausen Noise of a Non-oriented Electrical Steel (0.88 wt% Si) after Inclined Cold Rolling

Abstract

Inclined cold rolling was employed in this study to process a 0.88 wt% Si non-oriented electrical steel. After conventional hot rolling and annealing, the steel was cold rolled at various angles (i.e. 0°, 45°, and 90°) to the hot rolling direction (HRD), and the cold-rolled steel sheets were then annealed at different temperatures from 600°C to 750°C for 30 seconds to investigate the effect of annealing temperature on the texture and magnetic response of the material. The texture was measured by electron backscatter diffraction (EBSD), and the magnetic response of the steel was evaluated by magnetic Barkhausen noise (MBN) analysis. It was found that all the cold-rolled steels partially recrystallize at temperatures below 750°C, but the progress of recrystallization differs in steels cold rolled at different angles to the HRD, i.e. samples rolled at 45° to the HRD recrystallize faster than those after conventional rolling (0° to HRD) or cross rolling (90° to the HRD). The initial cold rolling texture (mainly the α-fibre and γ-fibre) may change to cube, rotated cube, rotated Goss or {111}<112> depending on the rolling scheme and the annealing temperature. The MBN root mean square values of the samples cold rolled at different angles to the HRD show substantial differences during the annealing process. At low annealing temperatures (600°C and 650°C), the anisotropy of MBN in the conventionally rolled steel is much higher than those after inclined rolling or cross rolling.