An insight into the origin of corrosion potential- A critical review

Measurement of corrosion potential of metals is a non destructive tool to understand the changes occurring on the corroding surface. Galvani (1791) observed the flow of current between dissimilar metals. Faraday (1820) gave quantitative relationship between metal dissolved or deposited with the quantity of electricity. Evans and Hoar (1932) proposed the heterogeneous theory of corrosion and Wagner and Trauvd (1938) presented the homogeneous theory of corrosion and the concept of mixed potential. In 1960 the corrosion potential was understood in terms of the area rations of anodic and cathodic sites. Pourbaix (1966) correlated the energetic of the corrosion process with solution pH. In 1978, it was seen that the corrosion potential to be dependent on solution parameters. Recently, the physical meaning of corrosion potential was understood in terms of ionic and electronic energy levels in metals. Various ideas presented are reviewed and discussed in detai