Simulation And Optimization Of Forging Process Of Nickel Based Superalloy Inconel 625

Forging parts are widely used in aerospace,transportation and chemical industries.New generation of nuclear and power equipments?high-efficiency and large-capacity aviation or navigational equipments?the oil?gas?chemical industry and other important industrial areas,put forward higher requirement for amount and performance of large forging products because of rapid developement.The traditional steel forging products has been unable to meet the industrial requirements of highstrength and light weight.Inconel 625,a kind of nickel-based superalloy,has gradually become the most popular material for large forgings parts.Even used at a high temperature of 600-1000?,it has excellent strength?corrosion and fatigue resistance?and good forging properties.However,the forging process of Inconel 625 is very complicated.A lot of parameters will affect the organization and performance of forging parts,including forging machine,heating temperature,forging energy,forging velocity,the lubrication and etc.Upsetting test and die forging test of Inconel 625 samples are carried out using SPR 400 screw press and DGH 40 counter blow hammer.The software FORGE is used to simulate the forging process using DGH 40 counter blow hammer.The results show that when the heating temperature is reduced from 1150? to 1050?,the deformation with the forging energy of 16 kJ reduces from 17 mm to 14.8mm and the maximum forging force increases from 3060 kN to 3192 kN.During the forging process,there exists a large forging force between dies and sample,and the phenomenon of hard impact is obvious.Increasing the heating temperature of the Inconel 625 samples accelerates the attenuation of forging force and weakens the hard impact phenomenon.After quenching process of the upsetting test,the grain size of Inconel 625 samples on the surface is about 100?m.The grain size in the heart is about 150?m.Simulation results also show that the grain size on the surface is 4 levles smaller than that in the heart.At the end of the die forging process,the final neck height is 111 mm.The difference between the measuring height and the nominal height is 6%.After quenching process of the die forging test,the average grain size on the surface is 230?m.The average grain size of 20 mm deep from the surface is 220?m.The average grain size in the heart is 150?m.The average grain size of burr is about 30?m,where the grain size is the smallest in whole part.The distribution of grain size is uneven;Simulations result show that the simulation parameters have great influence on the simulation results of neck height,including the parameter of stiffness?the parameter of energy regulation and the parameter of hammer model.While the parameter of equivalent mass and meshing parameter have little effect on the simulation of neck height.The parameter of stiffness?the parameter of energy regulation and the parameter of equivalent mass have a great effect on the simulation results of grain size.While the parameter of hammer model?meshing parameter and the parameter of initial grain size have almost no effect on the simulation results of grain size.According to the simulation results,the optimal simulation parameters for the hammer forging process are proposed.