HARMONIC-ANALYSIS OF CORRODING SYSTEMS CONSIDERING DIFFUSION PHENOMENA

Due to the nonlinear nature of a corroding system, a sinusoidal potent ial distortion results in an ac current response, which contains highe r harmonics. These harmonics can be measured and evaluated to obtain k inetic information, for example the corrosion rate and Tafel parameter s. A model was developed for the case that the anodic reaction was cha rge transfer controlled and the cathodic reaction was under mixed cont rol, i.e., both the charge-transfer and diffusion determine the reacti on rate. This model was used to obtain the corrosion rate and Tafel pa rameters for the corrosion of mild steel in an aerated sodium sulfate solution.