GH4720Li合金盘锻件的等温锻造工艺优化研究

Research on Process Optimization of Isothermal Forging for Superalloy GH4720Li Disc

基于MTS热模拟压缩试验得到的锻态GH4720Li合金热变形规律,利用数值模拟研究了等温锻造工艺参数对GH4720Li盘锻件温度场、形状及设备载荷等参数的影响规律。结果表明,1130℃为较合理的加热温度;锻造速度超过10mm/s、端面摩擦系数超过0.7都会造成锻件端面展开不充分、变形不均匀,导致局部升温过高并引起晶粒粗化;棒材的原始组织和加热均匀程度也会影响盘锻件的组织均匀性。基于模拟结果,优化了等温锻造工艺,并在500KN等温锻造液压机上成功制备出了GH4720Li涡轮盘锻件,晶粒度达到ASTM8级或更细,可以满足航空发动机的使用要求。

To optimize the process parameters of isothermal forging for GH4720 Li disc, hot simulation tests were carried out using MTS.Numerical simulation was also promote using Deform 2D to study the effect of forging parameters on radial load and characteristics of GH4720 Li disc such as appearance and temperature distribution. The results show that 1130℃ is the most suitable heating temperature; the forging rate should be controlled under 10mm/s, the friction coefficient between workpiece and die should be controlled under 0.7 to avoid larger grain size caused by nonuniform deformation and local temperature rise. Accepted GH4720 Li disc with improved surface quality and fine, uniform microstructure was gain after isothermal forging using optimized parameters by 500 MN presser.