GH4169高温合金的动态再结晶行为及微观组织演变研究  

Study on dynamic recrystallization behavior and microstructure evolution of GH4169 superalloy

作　　者：何文武[1] 杨春鹏 闫霄霞 焦永星 李飞[1] 陈慧琴[1] HE Wen-wu;YANG Chun-peng;YAN Xiao-xia;JIAO Yong-xing;LI Fei;CHEN Hui-qin(College of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《塑性工程学报》2020年第9期174-180,共7页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51575372);山西省重点学科建设经费资助项目(2019KJ029)。

摘　　要：借助Gleeble-1500D热模拟试验机,对GH4169高温合金进行等温热压缩试验,变形温度为1173~1373 K,应变速率为0.001~1 s^-1。并借助光学显微镜对不同热变形工艺条件下压缩后的试样进行微观组织观察,结果表明,变形温度和应变速率对合金动态再结晶的体积分数与晶粒尺寸都有影响。在应变速率为0.001 s^-1,温度为1173 K时,动态再结晶开始发生,温度增加到1273 K时,动态再结晶基本完成,同时动态再结晶平均晶粒尺寸由11μm增加到39μm。通过试验数据分析,建立了GH4169合金的双曲正弦本构方程,对流变应力曲线进行二次求导,获得了动态再结晶的临界应变,基于SellarsTegart本构方程建立了GH4169高温合金的动态再结晶动力学模型,并根据试验结果建立了动态再结晶晶粒尺寸模型,为优化GH4169高温合金高温条件下的变形工艺参数提供了理论依据。Isothermal thermal compression test for GH4169 superalloy was carried out on Gleeble-1500 D thermal simulator under the deformation temperature of 1173-1373 K and strain rate of 0. 001-1 s^-1. The microstructure of the specimen compressed under different thermal deformation conditions was observed by optical microscope. The results show that both deformation temperature and strain rate have effects on the volume fraction and the grain size of dynamic recrystallization. When the strain rate is 0. 001 s^-1 and the temperature is1173 K,the dynamic recrystallization occurs. When the temperature increases to 1273 K,the dynamic recrystallization is basically completed and the average grain size of the dynamic recrystallization increases from 11 to 39 μm. Through the experimental data analysis,the hyperbolic sinusoidal constitutive equation of GH4169 superalloy was established. The second derivative was carried out for the flow stress curve to obtain the critical strain of dynamic recrystallization. The dynamic recrystallization kinematics model of GH4169 superalloy was established based on the Sellars-Tegart constitutive equation. And a dynamic recrystallization grain size model was established on the basis of the experimental results,which provides a theoretical basis for optimizing the deformation process parameters of GH4169 superalloy under high temperature condition.

关 键 词：GH4169高温合金 流变应力 动态再结晶 微观组织演变 

分 类 号：TG314[金属学及工艺—金属压力加工]