FIELD: metallurgy.
SUBSTANCE: invention relates to the field of metallurgy, namely to the production of a sheet of electrical steel with a grain-oriented structure used as a material for iron cores of transformers. Hot rolling of a steel billet is carried out, having a chemical composition, wt.%: from 0.030 to 0.100 C, from 0.80 to 7.00 Si, from 0.01 to 1.00 Mn, from 0 to 0.060 in the sum of S and Se, 0.010 to 0.065 acid soluble Al, 0.004 to 0.012 N, 0 to 0.30 Cr, 0 to 0.40 Cu, 0 to 0.50 P, 0 to 0.30 Sn, 0 to 0, 30 Sb, 0 to 1.00 Ni, 0 to 0.008 V, 0 to 0.15 V, 0 to 0.20 Nb, 0 to 0.10 Mo, 0 to 0.015 Ti, 0 to 0.010 Bi, the rest is iron and impurities, to obtain a hot-rolled steel sheet, which is subjected to cold rolling. Decarburizing annealing is carried out in an atmosphere with a PH2O/PH2 oxidation state of 0.01-0.15 at a temperature of 750-900°C and a holding time of 10-600 s. An annealing separator including Al2O3 and MgO is applied at a MgO/(MgO+Al2O3) value of 5-50%, and the amount of water of hydration in the annealing separator is 1.5 mass% or less, and it is dried. Finish annealing is carried out at an oxidation state of 0.00010-0.2 in the case of an atmosphere including hydrogen, or a dew point of 0°C. or less in the case of an atmosphere consisting of an inert gas without hydrogen. The excess annealing separator is removed and an insulating coating is formed by applying a solution that includes mainly phosphate or colloidal silica, baking it at 350-600°C, and then subjecting it to heat treatment at 800-1000°C.
EFFECT: sheet has excellent magnetic performance and coating adhesion.
6 cl, 1 dwg, 10 tbl
