GH4169 Superalloy Multi-directional Forging Process And Simulation Study Of Microstructure Evolution

GH4169 high temperature alloy has good performance of hot processing and cold processing,it is often used to process and manufacture some parts with complex shapes and structures in the high-temperature application fields such as aerospace,in the process of use,the requirements on material structure and performance are also relatively high,so it is necessary to improve its organization and performance through special processing and treatment.The multidirectional forging process is a plastic processing method which compresses the forging in different directions and it is easy to obtain more fine and uniform grains and excellent mechanical properties.In this paper,the constitutive equation and dynamic recrystallization model of material are established based on the thermal compression experiment of GH4169 superalloy and import it into the deform simulation software in order to simulate the microstructure evolution of the closed polydirectional forging process of GH4169 superalloy.Through the hot compression experiment of Gleeble-3800,the stress and strain curves during the deformation process were obtained,and the stress and strain curves at different temperatures and different strain rates were analyzed,the constitutive equation and dynamic recrystallization model were established by analyzing the effect of temperature and strain rate on material properties and microstructure.By deform secondary development programming interface and user-defined subroutines,establish external files and material constitutive equation of dynamic recrystallization embedded into Deform simulation software,the software can simulate the material in the process of hot deformation recrystallization volume fraction(DRX)and the average grain size changes(AVD),which can quantitatively describe the microstructure evolution regularity.The change of equivalent strain,recrystallization integral number(DRX)and average grain size(AVD)of forgings in different passes under closed multi-direction forging process at 800??900?and 1000? was simulated by using the redeveloped Deform software.The results show that: under the same forging pass,the higher the temperature,the higher the degree of recrystallization,and the smaller the recrystallized grain size obtained;under the same temperature,the more forging passes,the larger the cumulative strain,the more recrystallization,and the smaller the recrystallized grain size.Comparing the grain size of the forgings obtained under the closed multi-directional forging process,the internal recrystallization law of the forgings was obtained,and the recrystallized grain size obtained by the simulation results was simulated by MATLAB software.Therefore,the change of grain size of the forging in the forging process can be more intuitively observed,and the strain non-uniformity and recrystallized grain inhomogeneity inside the forging obtained under different temperatures and different pass conditions are carried out.Comparative analysis to determine the best forging process and forging temperature.