ANODIC-DISSOLUTION OF METALS UNDER PULSED CONDITIONS IN THE PRESENCE OF AN ACTIVE-PASSIVE TRANSITION

Limiting pulsed currents in systems with an active-passive transition, where metal becomes passive after the limiting diffusion current is r eached, are studied by the example of anodic dissolution of iron in H2 SO4 Effects of the unipolar pulsed current parameters on the limiting diffusion current and of the pulsed potential parameters on the charge passing within one pulse are determined quantitatively. Passivation o f tungsten in methanesulfonic acid is not associated with concentratio n changes in the near-electrode solution layer. In this case, metal ha rdly dissolves under the action of unipolar pulses. Using bipolar puls ed current accelerates the dissolution of tungsten.