METHOD FOR APPLYING IRON-NICKEL-CHROMIUM COATINGS ON WORN SURFACES OF PARTS USING REVERSE CURRENT Russian patent published in 2022 - IPC C25D3/56 C25D5/18 

FIELD: coatings.

SUBSTANCE: invention relates to applying iron-based electrodeposited coatings and can be used in repair works. Method for electrodeposition of an iron-nickel-chromium alloy coating on a worn surface of a part includes preparing the worn surface of the part and subsequently electrodepositing the iron-nickel-chromium alloy coating from an electrolyte based on iron sulphate. Electrodeposition is performed from an electrolyte containing, g/l: H₂SO₄ 350 to 400, FeSO₄·7H₂O 150 to 350, NiSO₄ 35 to 75, Cr₂(SO₄)₃ 30 to 70, NaBr 3 to 5 g/l, ascorbic acid C₆H₈O₆ 3 to 7, crystal violet 1 to 2, at a temperature of the electrolyte of 18 to 20°C and deposition time from 1 hour or more until the predetermined coating thickness is achieved. An alternating asymmetric current at a frequency of 0.5 kHz and a density of 5 to 25 A/dm² with an asymmetry coefficient within the range from 1.2 to 5-6 is applied to the electrodes, wherein first the minimum value of said cathode-anode ratio is set from 1.2 and then gradually increased to a value of 5 to 6 with a value of minimum cathode-anode holding of 0.5 to 1 min.

EFFECT: good adhesion of coatings with the substrate, increase in the deposition rate and microhardness of the iron-nickel-chromium coating, reduction in the energy consumption.

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