SHEET OF ELECTROTECHNICAL STEEL WITH AN INSULATING FILM AND METHOD FOR MANUFACTURE THEREOF Russian patent published in 2022 - IPC C23C22/00 C23C22/24 C23C22/30 C23C22/74 

FIELD: shaping.

SUBSTANCE: group of inventions relates to a sheet of electrotechnical steel with an insulating film and variants of the method for manufacturing the steel sheet. Proposed is a sheet of electrotechnical steel with an insulating film containing Fe, Cr, an organic resin, and an organic reducing agent. In the insulating film, the molar ratio (Fe/Cr) of the content of Fe to the content of Cr ranges from 0.010 to 0.6. The variants of the method include applying a processing solution containing or consisting of a chromium compound with a mass ratio of trivalent chromium to total chromium of 0.5 or less, an organic resin and an organic reducing agent on at least one surface of a sheet of electrotechnical steel and heating the sheet of electrotechnical steel with the processing solution on the side of the steel sheet with a heating rate of 20°C /s or more in the temperature range from 100°C to 350°C for sintering the processing solution, producing an insulating film wherein the molar ratio (Fe/Cr) of the content of Fe to the content of Cr is from 0.010 to 0.6.

EFFECT: production of a sheet of electrotechnical steel with an insulating film exhibiting excellent resistance to chromium washing even when the insulating film is sintered using rapid heating.

5 cl, 1 tbl