High-temperature corrosion issues in advanced gas turbines systems intended for power generation

The new generation of land-based gas turbine systems to be based on technology developed by the Department of Energy's Advanced Turbine Systems (ATS) program is intended to represent a significant step forward in overall efficiency, economy of operation, and environmental compatibility. These advances require the hot gas path components to endure increased combustion temperatures for extended times with a minimum of cooling. Improved bottoming cycles including chemical recuperation and humidified air are also being considered. Whereas some of the required improvements in performance will rely on the transfer of component design, materials and processing from aircraft gas turbines, the specific duty cycle of the ATS machines will require increased emphasis on the use of thermal barrier coatings. The high-temperature corrosion issues raised by the severe operating conditions of these turbines and, in particular, those associated with the use of thermal barrier coatings are discussed.