Some Practical Aspects of Corrosion and Coatings in Utility Gas Turbines

Creep, fatigue and high temperature corrosion limits the useful life of high temperature components in large utility gas turbines. Protective coatings and thermal barrier coatings are applied in order to achieve predeterminable life periods without severe attack or damage of the structural material. Overhaul & repair methods and strategies help to further extend component lives economically. The growth rate of the protective oxide scale and its adhesion determine the useful life of a coating. Reliability and reproducibility are key factors to exploit their potential in using them as design elements. Repair techniques are applicable according to limits set by integrity requirements for the component. Proper performance can only be achieved with well controlled procedures following instructions which were defined after the results of careful investigations.