Fracture Analysis of Shaft in Gear Box

The fracture reason of the shaft in gear box was analyzed by means of chemical composition analysis, fracture analysis, metallographic examination and mechanical properties testing. The results showed that the fatigue fracture mode was determined, which originated from the sharp angle of the tool withdrawal chute. The right-angle withdrawal chute caused stress concentration. The unreasonable forging and heat-treatment process of material accelerated the fatigue fracture of the shaft.