Losses of Grain-Oriented Three Percent Si-Fe with Very High Permeability

Iron losses in 3 percent Si grain-oriented steel sheets with high magnetic flux densities, prepared by secondary recrystallization, are studied. Low iron losses, as measured in the rolling direction with a 1 kg/mm² tension applied, were obtained for several samples. Losses of samples on which glass films were deposited were larger than for laser-irradiated samples, probably due to the contribution of the glass film-iron interface to irreversible magnetization. Observations of magnetic domains in each phase under AC excitation indicated a lower domain density, a higher active magnetic wall number, and more uniform wall movement, than commercial samples.