GH4169合金变应变速率热变形过程动态再结晶动力学行为及建模

Kinetic Behaviors and Prediction Model of Dynamic Recrystallization in GH4169 Alloy during Hot Deformation at Variable Strain Rate

目的研究变应变速率高温变形过程中GH4169合金动态再结晶行为和晶粒组织的演变机理。方法在不同变应变速率工况下对GH4169合金进行高温压缩实验,分析了变形参数对动态再结晶行为与晶粒组织的影响规律,建立变应变速率工艺下GH4169动态再结晶动力学和晶粒尺寸预测模型。结果随着第一阶段真应变的增加或第一阶段/第二阶段应变速率的升高,GH4169合金动态再结晶程度降低,动态再结晶晶粒细化,平均晶体尺寸减小;建立的动态再结晶动力学模型的实验值和预测值之间的平均绝对相对误差(EAARE)和相关系数(R)分别为5.12%和0.988,建立的动态再结晶晶粒尺寸预测模型的预测值与实验值之间的EAARE和R分别为5.79%和0.992。结论对GH4169合金变应变速率高温变形过程中动态再结晶机理的研究,可用于指导GH4169合金时变工况下的高温塑性成形。

The work aims to study the dynamic recrystallization behavior and evolution mechanism of grain structure in GH4169 alloy during hot deformation at variable strain rate. High temperature compression test was conducted on GH4169 alloy at variable strain rate. The influences of deformation parameters on the dynamic recrystallization behavior and grain structure were discussed. The dynamic recrystallization kinetics and gain size prediction model of GH4169 alloy at variable strain rate was established. It was found that the dynamic recrystallization(DRX) degree of GH4169 alloy decreased with the increase of true strain at stage I, as well as the strain rate at stage I or II. Meanwhile, the DRX grain became refined and the average crystal size decreased. The mean absolute relative error(EAARE) and correlation coefficient(R) between the predicted value and the experimental value of the dynamic recrystallization kinetics model established was 5.12% and 0.988, respectively. The mean absolute relative error(EAARE) and correlation coefficient(R) between the predicted value and the experimental value of the dynamic recrystallization grain size prediction model was 5.79% and 0.992, respectively. The research on the dynamic recrystallization mechanism of GH4169 alloy in hot deformation at variable strain rate can be used to guide the high temperature plastic forming of GH4169 alloy under variable conditions.