This article presents common conventions and definitions in corrosion, electrochemical cells, cathodic protection (CP), electricity, and oxidation. Evans diagrams for impressed current CP in neutral or basic environment and galvanic or sacrificial CP, in both neutral or basic environment and acidic environment, are illustrated.

Alloys intended for use in high-temperature environments rely on the formation of a continuous, compact, slow-growing oxide layer for oxidation, and hot corrosion resistance. This article focuses on the issues related to high-temperature oxidation of superalloys used in gas turbine engine applications. It discusses the general methodologies used to evaluate oxidation resistance of materials. The article describes the performance characteristics of superalloys, single-crystal superalloys, and other high-temperature materials such as refractory metals and ceramics. It discusses hot corrosion of superalloys and airfoil degradation due to deposits resulting from ingested particles or sand. The article concludes with a discussion on the limitations of testing techniques and life prediction.