SHEET OF ANISOTROPIC ELECTROTECHNICAL STEEL AND METHOD FOR MANUFACTURE THEREOF Russian patent published in 2022 - IPC C23C8/14 C22C38/06 C22C38/34 C23C26/00 C23C28/04 H01F1/147 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely, to a sheet of anisotropic electrotechnical steel, and can be used as a core material for a transformer. The sheet of anisotropic electrotechnical steel comprises, % wt.: the main steel sheet; an intermediate layer of an oxide film including SiO₂, located on the main steel sheet, with an average thickness of 1.0 nm to 1.0 mcm; and an insulating coating with tension, located on the intermediate layer of an oxide film including SiO₂. The main steel sheet comprises, % wt.: 0.010 or less C, 2.50 to 4.0 Si, 0.0010 to 0.0100 acid-soluble Al, 0.012 or less N, 1.00 or less Mn, 0.02 or less S, if necessary, at least one element selected from: 0.01 to 0.50 Cr, 0.01 to 0.50 Cu, 0.001 to 0.05 Ca, 0.01 to 0.20 Sn, 0.001 to 0.010 B, and a residue consisting of iron and impurities. A time differential curve f_M(t) of the optical emission spectrum of the glow discharge of the metal element Al in the intermediate layer of an oxide film is defined for the sheet, satisfying the following formula.

EFFECT: formed insulating coating with tension has a high adhesion of the coating without deterioration of the magnetic characteristics and stability thereof on the surface of the sheet after final annealing.

3 cl, 1 dwg, 4 tbl, 3 ex