The Microstructure Prediction For The Precise Forming Process Of GH4169Alloy Blade

GH4169is a nickel-based deformed superalloy. Because of its excellentmechanical properties in the temperature range from-253to650℃, it has become a keymaterial for aviation and aerospace engine in China. The microstructure evolutionduring the deformation of the blade has been studied by experiments and simulation,and the study provides a theoretical basis for the actual production of blades.The hot deformation behavior and the microstructure of GH4169alloy have beenstudied systematically by the isothermal compression at the temperature range940~1100℃and strain rate range0.1~10s-1. During the deformation, the flow stressincreases with increasing strain. The the flow stress is gradually reduced after reachingthe peak stress. Under the same deformation conditions, the flow stress decreases withincreasing deformation temperature or decreasing strain rate. The dynamicrecrystallization grain size and fraction increase with increasing deformationtemperature or decreasing strain rate.The constitutive model and the microstructure evolution model were establishedthrough the hot compression experiments. The models were applied to simulate themicrostructure evolution of GH4169alloy blades.A subroutine with microstructure evolution model had been compiled usingFortran language, which can predict the microstructure evolution of GH4169alloy.Extrusion and forging process of GH4169alloy blade had been simulated byDEFORM-3D finite software. The influence of different parameters on microstructureevolution in the blade forming process had been analyzed. The results show that, in theextrusion stage, the percentage of dynamic recrystallization on blade body was100%,the grains are fine and uniform, the average grain size on blade body increased as theextrusion and the coefficient of friction increased, the influence of different parameterson the percentage of dynamic recrystallization is very little. In the forging stage, theaverage grain size on blade body is fine, and the percentage of dynamic recrystallizationis lager, the percentage of dynamic recrystallization increased as the forging speedincreased or the coefficient of friction decreased, the influence of forging speed on the grain size is little, the coarse-grain zone on the tenon expanded as the coefficient offriction increased.