In this lecture, you have been introduced to the thermodynamics and kinetics of corrosion and also to some of the common methods for preventing corrosion. Due to the constant contact of the metal surfaces with the environment and due to the fluctuating differences in the electrode potentials at various regions of the metal surface, regions of low reduction potentials readily get oxidized. The metal easily provides mobility to the electrons which move around until they can reduce H⁺ or O₂. The plots of E vs pH (Pourbaix diagrams) have wide applications in corrosion, electrodeposition, geological processes and hydrometallurgical extraction. These diagrams help us to analyze the regions where the metal is immune, where it is passive and where it gets corroded.

The kinetics of corrosion is governed by overpotentials, exchange current densties and corrosion currents. Prevention of corrosion is commonly achieved by protective coatings of polymer films, coating with other metals /galvanizing, passivation (by an adhering oxide layer), cathodic protection and the use of sacrificial anodes.