Electrochemical noise measurement and statistical parameters evaluation of stressed α-brass in Mattsson's solution

Electrochemical noise measured during the stress corrosion cracking (SCC) of alpha brass conducted in Mattsson's solution of pH 7.2 was investigated under free corrosion potential and at ambient temperature of 25 °C. The Burg's maximum entropy method was used to analyse the obtained readings. The electrochemical noise was observed as the spontaneous potential fluctuations. All the analysed result parameters of different standard deviations (spectrum, potential, magnitude), the mean potentials, total magnitude and the coefficient of variations (magnitude), appeared to give the clearest indication of the results and they bear close correlations with the already previously determined spectral density curves. Cracking of the specimen was indicated by the highest standard deviation peaks and the mean potential values. Scanning electron micrographs were made from the specimens' surface examinations. The observed corrosion behaviours as obtained from the results are related to the existing known SCC mechanism.