Abstract: The 0.1 mm thick Fe3.2%Si0.7%Al ultrathin nonoriented silicon steel were successfully produced by strip casting. The microstructure, texture evolution throughout the whole processing and effect of onestage and twostage cold rolling methods on magnetic properties were investigated in detail. The results showed that the microstructure of cast strip was characterized by typical columnar grains. Equiaxed ferrite grains were obtained after onestage cold rolling and annealing, and the associated texture was dominated by α*fiber and γfiber texture. The magnetic induction B50 of final annealed sheets was 1.681 T, which was much higher than that of ST100 in Japanese. The higher iron loss might be related to the lower purity of steel under laboratory conditions. Therefore, the magnetic induction of nonoriented silicon steels produced by strip casting significantly improved. Compared with the onestage cold rolling method, the grain size of final annealed sheets produced by the twostage cold rolling method was larger, and the unfavorable γfiber texture weakened, resulting in the iron loss obviously reduced and magnetic induction B50 increased from 1.681 T to 1.734 T.

Key words: nonoriented silicon steel, ultrathin strip, microstructure, texture, magnetic properties