A heavy duty prime mover engine of a pipeline pumping station seized during operation due to lube oil starvation. The seizure resulted in imminent damages to the engine components in the form of c racking of piston, cylinder liner, journal and main bearings and also in the quench cracks on some of the crank pin areas of the crank shaft. The extent of damage to the crank shaft of the engine was studied through conventional Nondestructive techniques such as Macroetching, DYE penetrant test, Magnetic particle inspection and ansata metallography. The study revealed macro & micro cracks and hard spots with hardness values as high as 500 VHN as against a normal value of 240 VHN at some locations on the journal areas of the crank pin. The shaft was reared by grinding the journal areas on a special purpose machine and simultaneously monitoring the hard spots for their size and hardness. The fitness for service of the shaft was ensured again through ansata metallography before the shaft was put to service.
The study thus revealed the efficacy of ansata metallography in detecting the cracks which otherwise could not have been detected through conventional techniques such as Magnetic particle inspection and Dye penetrant test.