GH4169孔挤压强化工艺过程数值模拟

在验证镍基高温合金GH4169中心孔挤压(CE)三维有限元模型正确性的基础上,利用单元删除法研究倒角、孔挤压-倒角顺序和铰削量3种具体工艺过程对孔边周向残余应力分布的影响。结果表明:孔边小于芯棒过盈量的初始倒角可以减小孔挤压后残余压应力;采用孔挤压-倒角的工艺顺序可以在孔边获得更小的残余压应力。铰孔可增大孔边入口处残余压应力,去除残余压应力极小值部分的材料。因此,在挤压强化后应尽量避免铰孔。

Numerical simulation on cold expansion strenghthening ,technology process of GH4169,

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.