Fatigue fracture analysis of gas turbine compressor blades

• A systematic work has been done to study the failure of a GTD450 gas compressor blade.
• Corrosion fatigue was found to be the reason for failure.
• Most of blade life time spends for formation of corrosion pits.

Gas turbine compressor blades are subjected to centrifugal and vibratory loads. This repeated loading and unloading can reduce the life of the compressor blades. An experimental procedure has been done to investigate the fatigue crack propagation in blades. Microstructure and fracture surface of the blade have been investigated by optical and scanning electron microscopy. Fatigue crack propagation considering the effect of corrosive environment has been studied. Environmental and micro-structural features revealed that the catastrophic fracture was initiated from the corrosion pit on the leading edge of the blade.