Fatigue Property of Railway Axles for Shinkansen Vehicles

Railway axles are ranked as the most important security parts because their fractures directly cause derailment of vehicles. However, press-fitted seats with wheels are necessary in axles due to the needs for structural function. Damages due to fretting fatigue occasionally occur on the seats in axles. Thus induction hardening and improvement of shape of press-fitted part have been adopted in axles for Shinkansen vehicles. In the present paper, a prediction method for fretting fatigue strength using fracture mechanics approach is constructed and validated. Moreover, full-scale induction hardened axles are fatigue-tested under 1.5 times higher stress than the allowable stress for design. Neither fracture nor magnetic particle flaws are indicated after the test.