An approach to galvanic corrosion

Galvanic corrosion behaviour of a bimetallic couple of steel and copper couple has been studied with different cathode to anode ratios. The classical understanding of the role of area-ratio on the development of galvanic corrosion has been observed to be modified when the total area experimentation the occurrence of a current-peak in the relation of galvanic current Vs area ratio has been observed. A physical interpretation of such current-peak has been put forwarded showing the intense localized corrosion near the peak. Further, a potential-current relation has been derived which shows that the entire galvanic system with the different area ratio would behave as a single electrode system under the influence of an apparent exchange current.