Decreasing the core loss of grain-oriented silicon steel by laser processing

Both experimental investigation into the lowering of the core loss of grain-oriented silicon steel sheets and theoretical analyses of heat conduction and elastoplastic stress have been conducted in this paper. The investigation indicates that either pulse laser or continuous-wave laser processing is able to reduce the core loss by more than 5% without damage to the coating and bending of sheet caused by unreasonable technical conditions. As a result, the theoretical analyses reveal that a reasonable heating time should be determined, within about 10(-8) and 10(-8) s, in order to prevent damage to the coating and bending of the sheet. (C) 1997 Published by Elsevier Science S.A.