Controlling Of Hot Forming Precision And Microstructure Of GH4169Superalloy Plate

With the rapid development of the aerospace industry, the good work performance and size precision of GH4169superalloy become more and more important. The plastic property of GH4169superalloy is pretty good in room temperature. Because the strength and hardness are high, cold deformation resistance and restore elasticity are large. However, hot deformation processing can reduce the deformation resistance and restore elasticity. It can improve forming precision too.In this paper, the hot deformation behavior, the microstructure evolution and hot forming process were studied through the hot deformation of GH4169superalloy.The material parameters, constitutive equation and microstructure evolution in different temperature and different deformation of GH4169superalloy could be got through high temperature tensile experiments. The evolution law of the grain in the different temperature was discussed, and the grain growth dynamics equation could be obtained. Process parameters were adopted by the result of finite element analysis. Hot deformation experiments were finished. Finally, the quality evaluation of workpiece was discussed.According to the data studied from high temperature tensile experiments, through the method of linear regression, the influences of flow stress caused by strain rate and temperature could be got. The relationships of lnσp-Inε,σp-Inε,lnsinh(ασp)-Inε and lnsinh(ασp)-1000/T were linear, but parallel degree of lnsinh(ασp)-Inε was the best. Therefore, the model of hyperbolic sine could be chose to describe GH4169superalloy. And its constitutive equation could be obtained.Through the observation of the microstructure of GH4169superalloy plate in different holding time, it was learnt that the higher temperature was, the faster grains grew; the shorter holding time was, the faster grains grew; and after that the rate of growing was slow. Through observating the microstructure of GH4169superalloy in different heating temperature and different tensile deformation, it could be got that GH4169superalloy plate had not significant directional character.And with the rising of temperature, grains would grow.With the increasing of the deformation,the grains would be refined.FEA simulation of hot deformation of GH4169superalloy plate was carried out on DEFORM3D. And it was decided that press rate was25mm/s and melt temperature was1020℃. The hot deformation experiment has been done according to the process parameters, and the precision of the part has been analysed. Through analyzing the defect and considering the expansion coefficient, the die has been modified and process parameters have been optimized. According to that, the hot forming experiment could be improved. The part that fulfill the precision and microstructure could be got.