Multi-objective optimization of parametric design for profile ring rolling process based on residual stress control

In the actual production process of the aerospace industry, machining deformation is common due to internal and external factors. Studies indicate that the release and redistribution of initial residual stresses within the component is the main factor distorting machining and service. Therefore, the reduction and homogenization of initial residual stresses are necessary to avoid machining distortion problems and to improve the overall quality of ring parts. The process of ring rolling and cooling tends to produce large and unevenly distributed residual stresses. The main research object of this paper is the TC4 titanium alloy profiled aerospace rolling ring. Firstly, a mechanical model of the radial rolling process was developed. Residual stress evaluation indexes matching the shape characteristics of profiled rings were designed. According to the continuous and penetration conditions, reasonable rolling process parameters and their range are determined. Secondly, a finite element model was established to simulate the rolling and cooling process. The simulation results were verified by corresponding rolling experiments based on the hole-drilling method. The experimental results were in high consistency with the simulation results. Finally, the response surface methodology and the finite element method were combined to jointly optimize the main process parameters of the rolling process. A second-order response prediction model was established for the ring parts with the numerical value and homogenization of the residual stresses as the integrated optimization objective. Based on the simulation results and the response model, the influence of each design variable on the residual stress of the ring is systematically analyzed and the optimal combination of process parameters is obtained and verified.