Simulation of extrusion strengthening of pressure equalizing hole of an engine compressor disc and design of extrusion heads

Statics solution algorithm was adopted in elastic-plastic finite element analysis program to simulate the extrusion strengthening process.Influences of parameters,such as friction coefficient,extrusion times,extrusion amount,restriction way,fillet radius and matching mode,on the residual stress distribution were analyzed.According to specific configuration of the pressure equalizing hole of the engine compressor disc,three different kinds of extrusion heads were designed,including:one-sided extrusion head,cylindrical extrusion head and T-shaped extrusion head.Two kinds of materials(stainless steel 1Cr11Ni2W2MoV and high temperature nickel-alloy ЗП742) were used to design and manufacture the simulation samples of sheets with holes.Edges of holes were strengthened using two above-mentioned coldworking techniques.The experiment results show that T-shaped extrusion techniques can efficiently and conveniently improve fatigue strength of sheets with holes.Numerical simulations were compared with experimental results,showing that statics general program can be used to simulate extrusion progress of sheet metal specimens with holes,and provide a guidance to extrusion strengthening research.