Evaluation of corrosion behaviour of selected metallic samples by electrochemical noise measurements

Electrochemical noise (EN) denotes spontaneous fluctuations in potential and current originating from the corrosion processes. In this work, EN was measured for three model metallic materials of known corrosion properties: Al, Fe and Fe30Al. Corrosion behaviour was assessed in neutral, acidic or alkaline solutions containing 4 wt% NaCl. Correlation between the electrochemical noise and corrosion intensity was established on the basis of appropriate treatment of the recorded numerical data and ex situ examination of the specimen surface. The parameter, referred to as EN resistance, allowed relatively simple and rapid evaluation of the corrosion behaviour of the investigated metallic materials.