Abstract: Based on high grade nonoriented silicon steel with Si content of 3.2 % , the influences of annealing time on the iron losses of P1.0/50 and P1.5/50 were studied. The results showed that：with the increase of the annealing time，the iron losses of P1.0/50 and P1.5/50 decreased first and then increased. The iron loss P1.0/50 became the lowest, which was 1.008 W/kg, when the annealing time was 110 s. While the lowest iron loss P1.5/50 was 2.601 W/kg when the annealing time was 90 s. The average grain size increased from 70 μm to 164 μm as the annealing time increased from 50 s to 130 s. The {110}〈001〉 orientation grain was small and much with short annealing heat time,and its texture component strength was high.While when the annealing time increased, the strengths of γ-fiber texture,{100}〈0vw〉 and {110}〈001〉 were increased，but the increasing amplitude was gradually slowed down. At the annealing temperature of 1 000 ℃ and the time 90 s,the Fe-3.2% Si non-oriented silicon steel can obtain excellent properties of low iron losses of P1.0/50 and P1.5/50 and high homogeneity.

Key words: high grade non-oriented silicon steel, annealing time, iron loss, texture