An Overview of Corrosion

In its simplest definition, corrosion is the deterioration of desired physicochemical properties of materials by the environment. This natural process can affect both metallic and nonmetallic materials (e.g., plastic, linings, and paint). Metallic corrosion, the main subject of this chapter, is a spontaneous phenomenon by which a metallic material returns to its stable thermodynamic state (i.e., metal oxides or metal sulfides). Most corrosion processes are electrochemical in nature, and their rate is greatly affected by the operating conditions. Based on the corrosion mechanism or the nature of the surrounding environment, metallic corrosion can be classified into different forms. However, corrosion is costly and can lead to serious damage. In order to eliminate or reduce the undesirable effects of corrosion, it is imperative to monitor this process and apply appropriate prevention methods. In this regard, the compromise between a less expensive method and a more effective one to protect against corrosion, as well as engineering fusibility, requires innovative methods. Given this view, this chapter provides an overview of the fundamentals of metallic corrosion through its mechanisms, costs, forms, study and monitoring, and preventative methods.