CHARACTERISATIONS OF CHROMIUM CARBIDE-BASED COATED COMBUSTOR LINER FOR GAS TURBINES
A gas turbine combustor liner experienced visible surface damages during its normal operation of 8000 hours. Small amplitudes of vibration during the operation contributed to a surface degradation, mainly wear. A chromium-carbide based hard coating was deposited via plasma spray technique on the outer surface of a combustor liner of a gas turbine engine. It was found that after the operation, the coating hardness had increased more than 30% compared to its minimum initial hardness and reached up to 744 HV particularly in the crossfire tube collar mating areas. Comparison between the coated and the uncoated liners were carried out in order to show how much the wear scars have been minimized throughout the operation under severe temperature of approximately 1, 500°C. It was found that in this study the coating of chromium-carbide is capable to reduce the wear damage due to the work hardening effect of the liner and their mating surfaces.