Hastelloy C-276合金热变形动态再结晶模型研究  

Dynamic Recrystallization Behavior of Hastelloy C-276 Alloy during Hot Deformation

作　　者：杜彬[1] 李德富[1] 郭胜利[1] 刘贤钙 冯策[1] 谢伟 

机构地区：[1]北京有色金属研究总院,北京100088 [2]宝钢集团特种材料有限公司,上海201900

出　　处：《稀有金属材料与工程》2016年第2期381-386,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50834008)

摘　　要：采用Gleeble-3500热模拟试验机研究了Hastelloy C-276镍基合金在不同变形条件下的热压缩流变应力曲线,热变形过程中发生了动态再结晶行为。利用加工硬化率-应力关系曲线确定了动态再结晶临界条件,采用Johnson-Mehl-Avrami(JMA)方程计算再结晶体积分数实验值,建立了C-276合金动态再结晶体积分数和晶粒尺寸预测模型。结果表明:C-276合金动态再结晶体积分数随着应变量的增加,呈现典型的"S型"曲线;获得临界应变条件表达式:lnε_c=0.144lnZ-7.173;动态再结晶体积分数表达式X_(drx)=1-exp{-1.4034[(ε-ε_c)/ε_(0.5)]^(2.58384)},预测值和实验值的平均误差为2.16%;晶粒长大表达式d_(drx)=6.58×10~3Z^(-0.168),预测值和实验值的平均误差为6.63%。The flow stress curve of Nickel base alloy Hastelloy C-276 during hot deformation was investigated by compression tests at varying temperatures and strain rates up to a true strain of 0.7 on Gleeble 3500 simulator.Dynamic recrystallization（DRX） occurred during hot deformation.The recrystallization critical conditions were determined by relationships between work hardening rate and stress curve.Experimental values of recrystallization volume fraction were calculated by Johnson-Mehl-Avrami（JMA） equation,and the dynamic recrystallization volume fraction model as well as the grain growth forecast model of Hastelloy C-276 alloy was established.The results show that the increment of recrystallization volume fraction is the typical ＂S＂ type curve with the increase of strain.The equation of critical strain conditions is established as lnε_c=0.144lnZ-7.173.The equation of recrystallization volume fraction is X_（drx）=1-exp{-1.4034[（ε-ε_c）/ε_（0.5）]^（2.58384）},and the average error of the predicted values and experimental values is 2.16%.The grain growth equation is d_（drx）=6.58×10~3Z^（-0.168）,and the average error is 6.63%.

关 键 词：HASTELLOY C-276合金 动态再结晶 组织演变模型 

分 类 号：TG146.15[一般工业技术—材料科学与工程]