SHEET OF ANISOTROPIC ELECTROTECHNICAL STEEL AND METHOD FOR MANUFACTURE THEREOF Russian patent published in 2022 - IPC C21D9/46 C22C38/00 C23C22/00 H01F1/147 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely, to a sheet of anisotropic electrotechnical steel, and can be used to manufacture the core of a transformer. Sheet of anisotropic electrotechnical steel comprises a steel sheet and an insulating coating formed on the steel sheet and consisting of oxides containing aluminium and boron; wherein said oxides contain crystalline oxides, and the maximum value of the ratio of emission intensities of boron to aluminium at the interface between the insulating coating and the steel sheet, as analysed by glow discharge optical emission spectrometry, is 2.5 to 4.0 greater than the ratio of the emission intensities of boron to aluminium in the insulation coating. Method for producing a sheet of anisotropic electrotechnical steel includes coating the surface of a steel sheet with a coating solution containing a boron source and an aluminium source with a mass ratio as calculated for Al₂O₃/B₂O₃ of 1.8 to 2.6; annealing the steel sheet in an inert gas atmosphere with a dew point of 0 to 40°C, containing hydrogen in an amount of 0 to 25 vol.% to a preset temperature in the range of 450 to 600°C with an average temperature increase rate of 2 to 5°C/s; then cooling said sheet to 200°C or less at a cooling rate of 10°C/s or more, and increasing the temperature of the steel sheet to 750°C with an average temperature increase rate of 10 to 100°C/s; and annealing the steel sheet in the temperature range of 750 to 1,000°C for 20 to 120 s.

EFFECT: high tensioning of the aluminium borate coating is provided.

2 cl, 1 dwg, 3 tbl, 2 ex