Determination of corrosion current density by the rate of cathodic depolarizer consumption

Resumo

The method of determination of metal corrosion rate, which does not require polarization of test specimen by an external power source, is described. The method involves the measurement of H⁺ ions consumption rate in the cathodic reactions at a constant pH value of solution, which is maintained by the compensating acid additives. The method application is demonstrated by two examples: the corrosion of iron in the weakly acidic sulfate and chloride solutions. Thus obtained results are compared with the data, which were determined by the methods of Tafel extrapolation and analysis of pre-Tafel portion of polarization curve.