Effect of initial residual stress on machining deformation of a casing part

Initial residual stress of blank is the main cause for the workpiece machining deformation. Based on the simplified equivalent model and the finite element analysis method, the effects of initial residual stress in bidirectional, axial direction and tangential direction on the deformation of an aluminum alloy conical case were studied respectively. The deformations of case were judged by flatness and roundness error of the end face of the case. From the results, it can be seen that the influence of the initial axial residual stress on the roundness error of the end face is greater than that of the radial residual stress; among all the errors, the roundness error of the large end face is much larger than that of other errors. It is shown that the roundness error of the large end face and the initial axial residual stress of the workpiece are the most important issues to be controlled in actual machining process. This conclusion has certain guiding significance for practical application.