This paper discusses the possibility of iron loss reduction in non-oriented electrical steel (NO) sheets with a composition corresponding to JIS grade 35A210, and estimates the optimum iron loss from experimental data. The hysteresis loss of processed pure NO steel was decreased by 0.27 W/kg from the present 35A210 standard. The 0.35-mm-thick NO sheets with random {100} textures and the optimum crystalline sizes of polycrystals and withoutprecipitation may decrease iron losses from 2.0 W/kg to 1.0 W/kg, because random {100} textures may reduce theeffects of steel surfaces on iron losses and make coercive forces low, and optimum crystalline sizes minimize total iron losses. If pure NO sheets with random {100} textures are used in motors, the iron loss of a motor may become low, notonly because those of the core materials are low, but also because the motor core characteristics improve as a result of uniform flux distributions due to the low coercive force and lower internal stress caused by magnetostrictions. The decrease in the hysteresis loss was about 20%, relative to the present 35A250 standard, in a 12-pole 9-slot motorwhere a core made of pure NO was excited by a NdFeB bonded permanent magnet, although the decrease in thehysteresis loss of the core material was only about 18%.
