FIELD: metallurgy.
SUBSTANCE: method involves slab rolling from electric steel in several passes till sheets of the specified thickness are obtained, primary recrystallisation annealing of sheet, secondary recrystallisation annealing, coating of sheet with treatment solution for application of insulating coating, and then sheet roasting. At that, treatment solution includes at least one phosphate chosen from phosphates Mg, Ca, Ba, Sr, Zn, Al, and Mn; colloidal silicon oxide in proportion of 0.5 to 10 moles in terms of SiO2 and water-soluble compound of vanadium in proportion of 0.1 to 2.0 moles in terms of V, per 1 mole of PO4 in phosphates.
EFFECT: application of coating of the above composition to the sheet from electric steel provides such properties as tensile stresses created with the coating, resistance to moisture absorption, corrosion resistance and iron space factor of transformer; the obtained properties are comparable with those obtained at application of chrome-containing treatment solutions for application of insulating coating.
7 cl, 2 ex, 2 tbl, 3 dwg
