Abstract: An ultra-thin grain-oriented silicon steel was subjected to different cold rolling processes and recrystallization annealing at 820 ℃, and the effect of cold rolling process on the magnetic properties and texture of the tested steel was studied. The results show that under different cold rolling processes, {111}<112> texture is formed and a large amount of shear bands is contained in the cold-rolled steels. In order to obtain excellent magnetic properties, different cold rolling processes need to be matched with different annealing processes. When the first pass reduction rate is 43%-52% and annealing time is 25 min, or the first pass reduction rate is 29%-37% and annealing time is 20 min, the microstructure with 70%-75% η-fibre texture and average grain size of 35 μm can be obtained, which leads that the magnetic properties of the ultra-thin grain-oriented silicon steel reach the optimal state, with the magnetic induction intensity B₈₀₀ ≥ 1.80 T and the iron loss P_1.5/400 ≤ 12.5 W/kg. The smaller reduction rate of first pass cold rolling, the shorter annealing time and the better uniformity of the microstructure. In industrial production, the reduction rate of first pass cold rolling could be properly reduced.

Key words: ultra-thin grain-oriented silicon steel, cold rolling process, texture, grain size, magnetic properties