Machining Distortion for Thin-Walled Superalloy GH4169 Caused by Residual Stress and Manufacturing Sequences

Abstract

The residual stress generated in the machining process has a passive influence on the machining accuracy of a thin-walled workpiece. Annealing treatment can release the residual stress induced in the machining process and suppress the machining distortion. However, there is no unified standard for whether annealing treatment is arranged after machining. In this paper, an analytical model for predicting the distortion caused by residual stress of thin-walled superalloy GH4169 is established. Then, the finite element method is applied to analyze the prediction results of the proposed model. It is found that the residual stress generated in the manufacturing process chain can cause large distortion for the thin-walled workpiece. Finally, combined with the law and principle of workpiece distortion, the annealing process planning of multiple manufacturing sequences of thin-walled superalloy GH4169 is formulated to suppress the machining distortion. For the machining process on one side of the workpiece, it is necessary to release residual stress. This is not necessary for the double-sided machining process. Research results can be used to optimize the manufacturing sequence of thin-walled components.

Keywords

• residual stress
• thin-walled workpiece
• distortion prediction
• manufacturing sequence
• process planning