Effect of Shot Peening Combined Vibration Finishing on Fatigue Behavior of GH4169Superalloy

Abstract:

The effects of shot peening and shot peening combined vibration finishing on the fatigue properties of GH4169superalloy are studied contrastively. The surface morphology, surface structure, roughness, microhardness and residual stress field of the sample were analyzed by scanning electron microscope, roughness profiler, microhardness tester, and X-ray stress tester, and the internal relationship and mechanism of surface integrity and fatigue performance are discussed. The internal relationship between surface integrity and fatigue properties and its mechanism were discussed. The results show that the composite treatment can improve the fatigue performance better. The composite treatment increases the room temperature fatigue strength of GH4169superalloy by 21.6％. Preheating at 500℃for 100h reduces the fatigue strength of composite strengthened GH4169superalloy by 6％, but it is still 14.29％ higher than that of the base material. That is to say, the composite treatment can effectively improve the fatigue resistance of GH4169superalloy under high temperature working conditions from room temperature to 500℃.

Key words:GH4169superalloy; shot peening; vibration finishing; surface integrity; fatigue