GH4169孔挤压强化工艺过程数值模拟

On the basis of verifying the correctness of the three-dimensional finite element model for the cold expansion (CE) of central hole fatigue specimen of nickel-based superalloy GH4169, the influences of chamfering size, the order of chamfering-CE process and the reaming amount on circumferential residual stress distribution around the hole edge were studied through element deletion method. The results showed that the initial chamfer size less than the interference amount of the mandrel can reduce the residual compressive stress after CE. Lower residual compressive stress can be obtained at the hole edge by using the CE-chamfering process. The reaming process can lead to the increase of residual stress at the entrance of the hole edge and the minimum residual stress may be removed. Thus, reaming should be avoided as much as possible after cold expansion strengthening.