Thermal Spray Coatings are widely used for the surface treatment and other applications. However the use of these coatings for high temperature applications is more recent one. The main advantage of the Plasma Spray Coatings is that it includes vide range of the materials that can be sprayed by this techniques. The book contains the research studies carried out basically regarding the applications of this coating to the energy generation systems to capture the boiler tube failures. The entire work carried out for this manuscript has been presented into nine chapters. First chapter contains the introductory remarks about hot corrosion problem faced by the various industries and especially in coal fired boilers. Second chapter begins with exhaustive survey of literature regarding various aspects and mechanisms of hot corrosion. Critical review of the existing studies and detailed behaviour of coatings to counteract the hot corrosion degradation have been made. This chapter is base for the decision to carry out the research in this area and to publish the reseutls as the data base for the researchers to carry out the further research. Third chapter deals with the experimental procedur.