Use of potentiostats in corrosion studies

A brief description of the electron‐transfer processes involved in the corrosion of metals is given. The relationship between the stable species formed in corrosion reactions, the pH of the aqueous solution involved, and potential of the metal, is referred to and the potentiostatic and galvanostatic methods of assessing electron‐transfer are contrasted. The development of various forms of potentiostat and the scope of the instruments are discussed, and examples given of their fields of use. The experimental techniques adopted to obtain current‐potential curves and to assess the rate of cathodic and anodic reactions are illustrated by reference to appropriate diagrams. A short section deals with the use of current/time transients for obtaining kinetic data especially for film growth and formation of pits.