An investigation of premature fatigue failures of gas turbine blade

• Investigation of the premature blade failure by mechanical, metallography and chemical analysis.
• Metallurgical characterization of blade material.
• Finite element analysis of the blade geometry.
• Identification of the steady-state stress concentration areas and the stress/strain values.
• Probable cause of failure and recommendations to mitigate such incidents.

A failure of a first stage compressor blade of a Gas Turbine Generator in a Gas Treatment plant caused severe mechanical damage to the compressor section and power supply troubles. In this paper, the blade failure is investigated by mechanical, metallography and chemical analysis. A finite element analysis is performed on the blade geometry to identify the stress concentration areas and the stress/strain values. The investigation outcomes provided the most probable cause of the premature blade failure and the recommendations to mitigate such incidents.