Failure of connecting pins of a compressor disc in an aero engine

This paper describes the failure analysis of pins connecting the second and third stage compressor discs in an aero-engine that had failed after 46,000 h of service. The investigation included metallography, microscopy (SEM), hardness and fractographic examination. Analysis revealed that failure was due to overloading by bending stresses and fretting owing to improper riveting of the pins. There was no indication of fatigue failure in these pins.