RU2022124684A - Method for hardening the surface of rolling and pressing tools using chromium-cadmium electrolyte - Google Patents

Claims (8)

1. A method of hardening the surface of a rolling-press tool using a chromium-cadmium electrolyte, which consists in the fact that the process is carried out with constant stirring in an electrolyte solution heated by an external heat source containing chromic anhydride CrO ₃ , sulfuric acid H ₂ SO ₄ , sodium fluorosilico Na ₂ SiF ₆ , and cadmium metal Cd, characterized in that chrome plating is carried out at an electrolyte temperature of 65°C and a variable current density, and an inorganic additive in the form of sodium dihydroxide Na ₂ Cr ₂ O ₇ is additionally introduced into the electrolyte composition with the following content of components electrolyte, g/l: chromic anhydride 180-200 sulfuric acid 0.8-1.1 sodium fluoride silico 4.5-5.5 sodium dichromate 25-30 cadmium metal 15-17, optimal program for changing the current when coating in a chromium-cadmium electrolyte: anodic pickling time - 30 s, Yes = 50 A/dm ² ; 1 cycle - 5 min; reverse current time between cycles - 5 s; the current rise time in other cycles is 7 minutes; the limits of change in current density when conducting the process under stationary conditions are 50-90 A/dm ² , temperature - 65°C.