Failure Analysis on Peeling off of Inner Ring of Front Bearing of Aero-engine Low-pressure Shaft

Peeling off was found to have occurred to the inner ring of the front bearing of low-pressure shaft of an aero-engine during fault detection after test. The cause for the peeling off was analyzed through fault tree. First, the chemical composition of raw material was analyzed, then the forging, heat treatment and grinding processes related to the peeling off were discussed, and the internal defects, hardness, quenching structure, surface morphology and residual stress of the inner ring were detected and analyzed. Finally, it is found that the peeling off is fatigue peeling off caused by forging defects. The outflow of defective products can be prevented by water immersion ultrasonic testing.