Corrosion Resistance Through the Application of Anti- Corrosion Coatings

Corrosion is the surface disintegration of metals/alloys within specific environment. Some metals basically exhibit high corrosion resistance than others and this can be attributed to several factors like their chemical constituents, the nature of electrochemical reactions itself and others. The corrosion resistance of metals can be defined in terms of its ability to withstand aggressive conditions. This determines to a large extent the operational lifetime of components in service. However, there are several definitions of corrosion and according to International Union of Pure and Applied Chemistry (IUPAC) "Corrosion is an irreversible interfacial reaction of a material (metal, ceramic, and polymer) with its environment which results in consumption of the material or in dissolution into the material of a component of the envi‐ ronment. Often, but not necessarily, corrosion results in effects detrimental to the usage of the material considered. Exclusively physical or mechanical processes such as melting or evapo‐ ration, abrasion or mechanical fracture are not included in the term corrosion" (Heusler et al., 1989). It is realized that this definition virtually include all engineering materials and it is considered as a wide definition. Hence, another definition is given by ISO 8044-1986 which states inter-alia: "Physicochemical interaction between a metal and its environment which results in changes in the properties of the metal and which may often lead to impairment of the function of the metal, the environment, or the technical system of which these form a part". (EFC Working Party 7: Corrosion Education, 2012).