Study of corrosion behaviour of mild steel and copper in thin film salt solution using the wire beam electrode

Abstract

A novel electrochemical method was developed to study of corrosion behaviour of mild steel and copper in thin salt solution film. In this paper, mild steel and copper wire beam electrodes were used to allow corrosion potential in the thin salt solution film to be measured directly. It was found that the distribution of corrosion potentials in the thin salt solution film is heterogeneous compared with a naked wire beam electrode in the bulk salt solution. At the early stage of the corrosion, the distribution of corrosion potentials in the thin salt solution film gradually shifted to a higher potential range. With increasing of immersion time, the distribution of corrosion potentials reached to a highest potential range, then it began to shift negatively to a lower potential range. It was pointed out that the distribution of corrosion potentials of copper in the thin salt solution film could be improved with increasing the degree of corrosion. However, for the steel wire beam electrode, with increasing the degree of corrosion, the distribution of corrosion potentials in the thin salt solution film tended towards heterogeneous distribution.