Gear blank: A case study of failure assessment

This work reports assessment of a failure of a cold forged gear blank reported from an industry. The damage is observed in the cold forged in form of cracks along the thickness direction. To investigate this problem, the visual examination, composition analysis, hardness, microstructure, residual stress measurement and non-destructive tests such as magnetic particle inspection, ultrasonic detection and radiographic tests were carried out and analyzed. The detailed comprehensive investigation revealed that the crack has occurred in the initial stage itself and acceptance criteria of the material to be evolved. The same has been discussed with the end user to ascertain that this type of failure should not occur again.