Numerical Simulation Of Thermal Stress And Deformation Of A Superalloy Blade Investment Casting

The residual stress and deformation of a nickel-based superalloy turbine blade has been investigated. The distributing of residual stress and deformation has been studied by a combined method of numerically simulation and experimental measurement. It can provide references for reducing residual stress and decreasing deformation.The 3-D model of the turbine blade has been built by Solidworks, and the interface ways between Solidworks and ProCAST are discussed. The file format of igs has a well fitness with the MeshCAST, and the mesh can satisfy the simulation of backward position very well.The residual stress is simulated by ProCAST. The predicated result is shown hereafter. The blade is suffering compressive stress mainly in the radial direction; The thicker part in the back of blade is bearing hoop tensile stress, while the basin of blade, air admission edge and exhaust edge are suffering compressive hoop stress. Wire-cutting residual stress measurement method has been used in order to get the residual stress on the surface of blade. The predication result has a better agreement with the experiment.The deformation induced by thermal stress of blade is simulated. The predicated result is shown hereafter. The reserved bow deformation and the furl deformation have been found. The distortion also happens in the body of blade. The flange's warp takes place, too. The templates and chucking appliance are applied to measure the deformation. The predicated result agrees with the experimental measurement. Hereby an improved process is offered to balance the deformation.The effects of cooling condition and preheated temperature of the shell are simulated by ProCAST. At a constant pouring temperature, it can minish the residual stress and deformation by putting felt outside of blade or setting higher preheated temperature of shell.