1. Electrochemical Fundamentals of Corrosion and Corrosion Protection

In this chapter, we outline the corrosion process and corrosion protection, which are the basis of the more quantitative treatment presented in the following chapters. The corrosion process in aqueous solution is made up of electrochemical reactions consisting of oxidation of metallic materials and reduction of environmental substances. For the corrosion process, the local cell model has been proposed in which anodic oxidation of the metallic material and cathodic reduction of the environmental substances occur at different sites on the material and the currents of the both reactions are same as each other. The following topics are concisely described: (1) corrosion electrochemistry, (2) classification of corrosion, (3) synergistic effect of the mechanical action on corrosion, (4) corrosion protection, and (5) hydrogen entry into the metallic material and delayed rupture.