Fundamentals of Corrosion Kinetics

Abstract

This chapter presents basic aspects of the electrochemical kinetics underlying metallic corrosion, including activation controlled kinetics and mass transport effects. Mixed potential theory, the foundation of our understanding of corrosion electrochemistry, is discussed in terms of the half reactions for anodic dissolution and the typical cathodic reactions in aqueous solutions. Mixed potential theory is then used to explain the typical form of measured potentiodynamic polarization curves. The inhibition of corrosion by the presence of species added to the environment is discussed in terms of reductions in the kinetics of one or more of the corrosion reactions. The final topic is passivity, or the spontaneous formation of a thin protective surface film, which can be viewed as a form of anodic inhibition.