The Study On The Control Of Uniformity Of Microstructure Of GH4169Alloy Turbine Disc

Turbine disk is the key component of aircraft engine and its performance is highlyrequired. However, turbine disk forgings often exists different levels of nonuniformmicrostructure in the process of production, which vastly lower the usability of turbinedisk, so the research on the nonuniform microstructure in the process of turbine diskforging has been paid more and more attention.GH4169Alloy is the most commonly used material of Turbine disk, which has beenthe most widely and maximumly applied high-temperature alloy material in such fields asaviation and aerospace at present. This paper considers GH4169alloy turbine disk as theresearch object and mainly focuses on the research of nonuniform microstructure in theproduction of turbine disk.This paper obtained the stress-strain curve of GH4169alloy by applying Gleeble3500thermo-mechanical simulator to do a hot compression texts on GH4169alloy, whosedeformation temperature was at900to1100℃and the strain rate was at0.001s-1to10s-1.Established the constitutive equation of GH4169alloy by analyzing the influence rule ofthermal deformation parameters on flow stress. This paper established the processing mapof GH4169alloy based on the hot compression experimental results and the dynamicmaterial model and related theories of processing map.By studying the processing map ofGH4169alloy, this paper obtained reasonable thermal processing under the testingdeformation conditions: the deformation temperature is at1000to1100℃and the strainrate was at0.001s-1to0.1s-1.The relationship between the thermal deformation parameter and microstructure ofGH4169alloy was studyed by analyzing the metallographic of hot-compression testedsample of GH4169alloy. Established the dynamic recrystallization mathematical model、the dynamic recrystallization grain size model and the grain growth model of GH4169alloy by regression analysis.According to the established models for microstructure evolution of GH4169alloy,the material model of GH4169alloy based on Deform-3D was established. Studied the relationship between forging process and microstructure of GH4169alloy turbine diskforgings by applying the numerical simulation method. Studied the fundamental cause ofthe microstructure from different parts of the turbine disk forgings by analyzing thedeformation characteristics from different parts of the turbine disk forgings. An evaluationmethod was given to evaluate the uniformity of microstructural of turbine disk forgings,and get a superior forging process of GH4169alloy turbine disk by using this method.