| 摘要 |
PROBLEM TO BE SOLVED: To irradiate the surface of a thick grain oriented silicon steel plate of >=0.30 mm plate thickness with a laser beam and to improve the iron loss characteristics therein. SOLUTION: In the method for producing a grain oriented silicon steel plate in which a grain oriented silicon steel plate having >=0.3 mm plate thickness is irradiated with a laser beam and magnetic domain fractionization is executed, the cumulative irradiating energy density at the optional point on a scan line in the laser beam irradiation is controlled to the range from (69t+44) to (104t+66)(mJ/mm2) to the plate thickness (mm), and moreover, the power density of the laser beam is controlled to <=(168t+106) kW/mm2. The irradiating diameter of the laser beam is preferably controlled to 6 to 10 mm major axis and 0.25 to 0.35 mm minor axis in the case of an oval and to 0.4 to 0.5 mm in the case of a circle. |
