Grain-oriented electromagnetic steel sheet with improved watt loss
AssigneeNippon Steel Corporation
InventorsTadashi Ichiyama, Shigehiro Yamaguchi, Tohru Iuchi, Katsuro Kuroki
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Abstract
In a method of producing a grain-oriented electromagnetic steel sheet, a laser beam is irradiated onto the steel sheet, which has been subjected to a final high temperature annealing in order to approximate the crystal orientation of the sheet in a (110), [001] orientation. Because of the laser beam irradiation, regions of high dislocation density are locally formed in the steel sheet and subdivide the magnetic domains, with the result that a low watt loss is achieved.
Claims15
In a method of producing a grain-oriented silicon-steel electrical sheet by cold rolling a silicon-steel sheet, with intermediate annealing if necessary, to a standard electrical sheet thickness, decarbonizing the sheet if necessary, and subjecting the sheet to a final high-temperature anneal, so as to produce a grain-oriented silicon-steel electrical sheet having a plurality of magnetic domains;
- wherein the improvement comprises momentarily irradiating the finally annealed sheet by a laser beam so as to subdivide said domains to an extent appreciably improving the watt loss of the finally annealed sheet as compared to the watt loss it had prior to said irradiating.
A method for improving the watt loss of a silicon-steel electrical sheet of the grain-oriented type produced by a process comprising cold-rolling the sheet completely to a commercial standard electrical sheet thickness and a final high-temperature anneal so as to provide the sheet with a substantially (110) [001] structure having a plurality of magnetic domains;
- said method comprising irradiating said sheet with laser beam energy so as to subdivide said magnetic domains to a degree improving the watt loss of the sheet without any change in the shape of the sheet surface.
Dependencies are inferred from the claim text.