PRODUCTION METHOD OF GRAIN-ORIENTED ELECTRIC STEEL SHEET Russian patent published in 2009 - IPC C21D8/12 C21D1/09 

FIELD: metallurgy.

SUBSTANCE: for reduction of power losses in sheet and providing of magnetostriction of lower level it is implemented focusing of laser beam on surface of sheet and scanning by it of sheet surface in the direction of sheet width for giving to it in cycling duty of residual mechanical stress, herewith laser beam is received by means of cyclic modulating of power of CW laser with usage herewith modulation period Tm, specified time space Tf, where power is 10% or less from maximum value Pp, and difference between Tm and Tf: Tn=Tm-Tf for definition of volume of power modulating Dp, as Dp=Tn/Tm × 100% in form of temporal wave of specified module by power beam, that volume of power modulating Dp is from 70 up to less than 100%, and minimal value Pb of power of specified laser beam is 10% or less from maximum value of Pp. Maximal power density Ppd of laser beam on surface of sheet is defined b means of focus area S of this laser beam and peak value Pp as Ppd=Pp/S. Ppd is from 1·10² up to 1·10⁴ watt/mm².

EFFECT: development of advantageous process of manufacturing if sheet from grain-oriented electric steel.

3 cl, 6 dwg