The kinetic parameters of the anodic dissolution of Fe in the active region, and of H2 evolution, in Cl−-, Br−-containing solutions, have been measured by quasi-stationary and by perturbation methods. It is shown that Cl also inhibits Fe corrosion in acid solution. Tafel slopes for the anodic curve up to 114 mV have been measured. In contradiction to Fischer and Lorenz, a sharp change of the quasi-stationary anodic curve to a less polarizable behaviour can be observed in Cl−-containing acid solutions with a sufficiently high concentration of Cl −. Perturbation measurements show such effect.This behaviour can be explained by the suggestion of Heusler that Cl− desorption takes place.A summary of the effect of neutral salts on the kinetics of electrochemical reactions is given with X−-ion addition at constant pH, the hydrogen overvoltage goes throuph a maximum and the corrosion velocity of Fe a minimum. This process is governed by the complex influence of the added neutral salt on the kinetics of the electrochemical reactions.
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