GH4065A高温合金惯性摩擦焊接本构模型及热变形行为研究

Constitutive Model and Thermal Deformation Behavior of GH4065A Superalloy in Inertia Friction Welding

目的为了更好地描述GH4065A合金在惯性摩擦焊接过程中的塑性流变行为,建立适用于GH4065A高温合金惯性摩擦焊接的材料本构关系,并探究焊接过程中材料的热变形行为。方法采用Gleeble-3800热模拟机对GH4065A高温合金在1000~1150℃温度和0.01~10 s^(−1)应变速率下进行等温热压缩试验,基于实测的流动应力-应变数据,分析不同温度和应变速率下的材料流变特性,对比了GH4065A合金的Johnson-Cook本构模型和Arrhenius双曲正弦本构模型的准确度,并且将建立的Arrhenius本构模型应用到GH4065A的惯性摩擦焊接有限元仿真中。结果GH4065A高温合金在高温下表现出加工硬化与动态软化的复杂相互作用,其流变应力随应变速率的上升而增大,随变形温度的上升而减小。基于Arrhenius模型的有限元模拟结果与IFW试验结果吻合较好,镦粗量的有限元模型的误差为5.6%。结论通过在不同温度和应变速率下对GH4065A高温合金的流变特性进行分析,发现该合金在高温条件下表现出加工硬化和动态软化的双重行为。采用Arrhenius本构模型对GH4065A合金的流变行为进行了描述,并通过有限元仿真验证了该模型的准确性。表明该模型能够有效地预测GH4065A合金在惯性摩擦焊接过程中的热变形行为,为焊接工艺的优化提供了理论支持。

The work aims to establish a material constitutive relationship suitable for GH4065A in IFW and investigate its thermal deformation behavior during the welding process,so as to better describe the plastic flow behavior of GH4065A alloy during inertia friction welding.Isothermal hot compression tests were conducted on GH4065A alloy using the Gleeble-3800 thermal simulator at 1000 to 1150℃and strain rates of 0.01 to 10 s^(−1).Based on the measured flow stress-strain data,the mate-rial's rheological characteristics under different temperatures and strain rates were analyzed.The accuracy of the Johnson-Cook constitutive model and the Arrhenius hyperbolic sine constitutive model for GH4065A alloy was compared.The established Ar-rhenius constitutive model was applied to the finite element simulation of GH4065A’s inertia friction welding.GH4065A exhib-ited a complex interaction between work hardening and dynamic softening at high temperature.The flow stress increased with the rise in strain rate and decreased with the increase in deformation temperature.The finite element simulation results based on the Arrhenius model showed good agreement with the IFW experimental results,with an error of 5.6%in the upset volume.Through the analysis of the rheological behavior of GH4065A high-temperature alloy under different temperature and strain rates,it is found that the alloy exhibits both work hardening and dynamic softening behavior at high temperature.The Arrhenius constitutive model is used to describe the flow behavior of GH4065A alloy,and its accuracy is validated through finite element simulation.The results indicate that this model can effectively predict the thermal deformation behavior of GH4065A alloy dur-ing the inertia friction welding process,providing theoretical support for the optimization of welding techniques.