ABSTRACT
A large number of metallic components in a variety of industrial installations are exposed to oxidizing environments at elevated temperatures. Examples of such components are gas turbine blades and vanes, superheater and reheater tubes of boilers, reformer tubes, heat exchanger tubes, parts for fuel conversion and power-generating units, and parts for petrochemical industrial applications. Sometimes these components are exposed to mixed environments which simultaneously exhibit oxidizing, carburizing, and sulfidizing capacities. The extreme conditions imposed on metals and alloys can be exacerbated by thermal cycling and sudden high-temperature excursion. This may eventually reduce the service life of metallic components, leading to sudden failure and rupture. Furthermore, a type of accelerated corrosion, known as ''hot corrosion,'' is often encountered in gas turbine components in the presence of deposits of molten salts, such as sulfate, nitrate, and vanadate.
