修正的Zerilli−Armstrong、Johnson−Cook及Arrhenius本构模型对C-276哈氏合金流变应力的预测

Flow stress prediction of Hastelloy C-276 alloy using modified Zerilli−Armstrong,Johnson−Cook and Arrhenius-type constitutive models

为进一步揭示C-276哈氏合金的高温流变行为,在温度为1223~1423 K,应变速率为0.01~10 s−1条件下对该合金进行热拉伸测试,并基于修正的Zerilli−Armstrong模型、Johnson−Cook模型和应变补偿的Arrhenius模型,分别构建相应的本构方程来反映C-276哈氏合金高温流变应力。同时,采用相关系数(r)和绝对误差(Δ)对这3个模型的预测精确性进行评价,计算结果显示Zerilli−Armstrong、Johnson−Cook和Arrhenius本构模型的r值分别为0.935、0.968和0.984,Δ值分别为13.4%、10.5%和6.7%。此外,对比分析在0.1~0.5应变范围内流变应力的实验值与预测值,结果进一步表明改进的Arrhenius模型对C-276哈氏合金的高温流变行为具有较好的预测能力。

To better understand the hot deformation behaviors of Hastelloy C-276 alloy under elevated temperatures,hot tensile tests were carried out in the temperature range of 1223−1423 K and the strain rate range of 0.01−10 s^−1,respectively.Based on the modified Zerilli−Armstrong,modified Johnson-Cook,and strain-compensated Arrheniustype models,three constitutive equations were established to describe the high-temperature flow stress of this alloy.Meanwhile,the predictability of the obtained models was evaluated by the calculation of correlation coefficients(r)and absolute errors(Δ),where the values of r for the modified Zerilli−Armstrong,Johnson−Cook,and Arrhenius-type constitutive models were computed to be 0.935,0.968 and 0.984,and the values ofΔwere calculated to be 13.4%,10.5%and 6.7%,respectively.Moreover,the experimental and predicted flow stresses were compared in the strain range of 0.1−0.5,the results further indicated that the obtained modified Arrhenius-type model possessed better predictability on hot flow behavior of Hastelloy C-276.