Abstract
A method for calculating the thickness of the vapor-gas envelope formed around the cathode during electrolytic-plasma heating has been developed, taking into account the energy characteristics of the process. The proposed approach is based on an analysis of the energy balance in the near-cathode region and considers the effects of current density, voltage, thermophysical properties of the electrolyte, and heattransfer parameters on the conditions of evaporation and vapor-gas mixture formation. Experimental studies were carried out under cathodic heating of steel 20 samples in a Na₂CO₃ solution at 100-300 V with simultaneous recording of temperature and electrical parameters. Numerical modeling of current and energy distribution in the near-cathode region was performed in COMSOL Multiphysics. Relationships between the vapor-gas envelope thickness and the discharge energy parameters were established, and it was shown that its growth is accompanied by the transition from nucleate to film boiling of the electrolyte and by an increase in the cathode heating intensity. The obtained results can be used for selecting electrolytic-plasma processing regimes and for modeling thermal processes in the near-cathode zone.