The effects of recrystallization texture and grain size on magnetic properties of 6.5 wt% Si electrical steel

Abstract

Cold rolled sheets of high silicon electrical steel (Fe-6.5wt% Si alloy) with thicknesses of 0.2–0.4mm were fabricated by directional solidification and rolling, and the microstructure, texture and magnetic properties of the sheets annealed at 700–1300°C for 1h were investigated. The roles of recrystallization texture and grain size in influencing the magnetic induction and core loss were clarified. All the samples had strong {100} recrystallization texture with volume fraction of 18.3–47.3% and exhibited high magnetic induction and low core loss. For the samples with a thickness of 0.2mm after annealing at 800–1200°C, the magnetic induction B8 and the core loss P10/50 reached 1.273–1.378T and 0.49–0.84W/kg, respectively. The grain size played a much more important role in the core loss than recrystallization texture. The average grain size to seek minimum core loss P10/50 was 536–615μm in the high silicon electrical steel sheets with thicknesses of 0.2–0.4mm, which was larger than 100–200μm for the electrical steel with common silicon content. The magnetic induction B8 of the samples improved with an enhancement of {100} recrystallization texture, but reduced with an increase of average grain size. The effect of recrystallization texture on the magnetic induction B8 was much greater than that of grain size.