METHOD OF HARDENING SURFACE OF ROLLING-PRESS TOOL USING CHROMIUM-CADMIUM ELECTROLYTE Russian patent published in 2024 - IPC C25D3/04 

FIELD: various technological processes.

SUBSTANCE: invention relates to electroplating and can be used for surface hardening of rolling-pressing tools. Method involves application of a chrome coating on the surface of an electrolyte containing, g/l: chromic anhydride 180–200, sulfuric acid 0.8–1.1, sodium fluorosilicate 4.5–5.5, sodium dichromate 25–30, cadmium metal 15–17, while chromium plating is carried out with constant stirring in heated using an external heat source in an electrolyte solution at temperature of 65 °C and variable current density, with anode pickling time 30 s, anode current density Da 50 A/dm², one cycle time 5 min, time of reverse current between cycles is 5 s, time of current rise in other cycles is 7 min and within the limits of change of current density Dc when conducting process in stationary conditions is 50–90 A/dm².

EFFECT: increased wear resistance of chrome coating with improvement of physical and mechanical properties, in particular, non-porosity, plasticity, coating also has high hardness, minimum stress, minimum reduction of fatigue limit of chrome steel, which contributes to improvement of consumer properties of tool; invention increases efficiency in production of seamless pipes.

1 cl, 33 dwg, 4 tbl