锻态C-276镍基合金热变形行为及热加工图

为研究锻态C-276镍基合金的热变形行为,采用Gleeble-3180D热模拟试验机对该合金在变形温度950~1200℃以及应变速率0.01~10 s^-1条件下进行一系列热压缩实验。结果表明,合金的流变应力曲线都呈现明显的动态再结晶特征,并且流变应力随变形温度的提升或者应变速率的下降而降低。根据Arrhenius模型构建该合金峰值应力下的本构方程,得出合金的变形激活能为510.484 kJ/mol。依据材料动态模型绘制合金在0.6应变下的热加工图,并结合组织分析提出该合金最优的热加工参数为(1100℃,0.01 s^-1)以及(1150℃,0.01~1 s^-1)。另外,合金的组织变化规律表明,温度的增加或应变速率的降低能够促进合金的动态再结晶晶粒的形核与长大。

Hot deformation behavior and processing map of forged C-276 nickel-based alloy

In order to investigate the hot deformation behavior of a forged C-276 nickel-based alloy,a series of hot compression tests at temperatures of 950-1200℃and strain rates of 0.01-10 s^-1 were carried out by Gleeble-3180D thermal simulator.The results show that the flow stress curves of alloy exhibite typical dynamic recrystallization characteristics and the flow stress decreases with the deformation temperature increasing or the strain rate reducing.Constitutive equation of C-276 alloy is constructed using peak stress according to Arrhenius model,and the deformation activation energy is 510.484 kJ/mol.At the strain of 0.6,a processing map is established based on dynamic material model.Combining with microstructure analysis,the optimum hot working parameters of C-276 alloy are(1100℃,0.01s^-1)and(1150℃,0.01-1 s^-1).In addition,the microstructural change law of alloy indicates that the increase of deformation temperature or the reduce of strain rate can facilitate the nucleation and growth of dynamic recrystallization grain.