METHOD FOR ELECTROCHEMICAL DEPOSITION OF CHROME COATINGS FROM SELF-REGULATING ELECTROLYTE BASED ON TRIVALENT CHROMIUM COMPOUNDS

摘要

FIELD: machine building.;SUBSTANCE: invention relates to electroplating and can be used in machine building, instrument making and other industries for application of protective-decorative coatings on metals and alloys. Method of electrochemical deposition of chrome coatings on metals and alloys involves electrolysis in an aqueous solution containing, mol/l: chromium (III) chloride 0.25–0.3, formic acid 0.6–0.8, boric acid 0.7–0.9, ammonium or alkali metal chloride 3–4, ammonium or alkali metal bromide 0.4–0.6, dihydroxohexaformate tetriochrome (III) chloride 0.4–0.6. Electrolysis is carried out at electrolyte temperature of 20–22 °C, pH 1-2.5 and operating current density of 5–50 A/dm².;EFFECT: invention increases stability of the electrolyte composition during long-term operation and widens the range of operating current densities.;3 cl, 2 tbl, 3 ex, 1 dwg