Evaluation of the degradation mechanisms of materials/coatings of gas turbine components of turbomachinery operating with unconventional fuels

The current study focused on the high-temperature oxidation characteristics of Ni and Co-based superalloys in dry and wet conditions, using both continuous and discontinuous approaches. In the dry high-temperature oxidation state, a continuous flow of air flows inside the furnace, whereas in the wet high-temperature oxidation condition, a mixture of air and water vapor streams inside the furnace at 982 °C. In the continuous approach, all samples were placed inside a furnace at 982°C with a continuous flow of air and water vapor and extracted after a specific time such as 500, 1000, 2000, 3000, and 4000 hours, whereas, in the discontinuous approach, all samples were extracted and reinserted into the furnace after each week at 500, 1000, 2000, 3000, and 4000 hours. The oxide thickness, phases, nature, composition, and morphology of oxides were assessed by energy dispersive x-ray spectroscopy (EDS), optical microscopy, scanning electron microscopy (SEM), weight gain analysis, oxide thickness analysis, and x-ray diffraction (XRD).