Research on deformation control method during the machining of turbine disk fir-tree slot

Internal residual stress formed during powder metallurgy preparation of turbine disk blank. It was an important factor affecting the dimensional accuracy and service stability of fir-tree slot. After analyzing the mechanism of deformation caused by material residual stress in machining process, this paper puts forward the combined machining technology of deformation control of "WEDM + Grinding". According to the machining deformation characteristics of fir-tree slot, V-groove experiment was designed to measure the residual stress deformation law of turbine disk. Furthermore, the machining technology of using large margin coarse cutting to release stress and then using small margin precision cutting to repair deformation was put forward. This method can effectively control the residual stress and deformation in tenon groove machining and ensure the uniform margin in grinding process. The remelting layer was removed by grinding and the precision was ensured so that the fine machining allowance of turbine disk mortise and groove can be well consistent. Finally, the grinding accuracy was improved by more than 50% compared with the design requirements.