GH4698高温合金变形中的流变行为及显微组织  

Rheological behavior and microstructure of super alloy GH4698 during deformation

作　　者：左正 郭淑玲 张文文[2] 刘鑫刚[2] Zuo Zheng;Guo Shuling;Zhang Wenwen;Liu Xingang(Wanhang Die Forging LLC,China National Erzhong Group Co.,Deyang 618000,China;College of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,China)

机构地区：[1]中国第二重型机械集团公司万航模锻有限责任公司,四川德阳618000 [2]燕山大学机械工程学院,河北秦皇岛066004

出　　处：《锻压技术》2020年第1期193-199,共7页Forging & Stamping Technology

基　　金：国家科技重大专项基金资助项目(2012ZX04010-081)

摘　　要：在热模拟试验机上进行了高温压缩试验,研究了GH4698高温合金在不同变形温度(950~1200℃)和应变速率(0. 01~10 s^-1)条件下的流变行为,建立了基于流变曲线的本构方程及以动态材料模型为基础的热加工图。借助扫描电镜和背散射电子衍射技术(EBSD)对变形后试样进行组织分析。结果表明:GH4698高温合金流变应力随着变形温度的降低和应变速率的加快而逐渐增加。在变形温度为1000~1200℃、应变速率为0. 01~0. 05 s^-1的热变形条件下,GH4698高温合金具有较佳的热加工行为。在高、低功率耗散率区域中,随着功率耗散率值的增加,动态再结晶百分数均会增加,再结晶平均晶粒尺寸增大,大角度晶界分数增加。High temperature compression test was conducted by the thermal simulation test machine,and the rheological behavior of super alloy GH4698 under different deformation temperatures( 950-1200 ℃) and strain rates( 0. 01-10 s^-1) was studied. Then,the constitutive equation based on rheological curves and the thermal processing map based on dynamic material model were established respectively,and the microstructure analysis of deformed specimens was conducted by scanning electron microscopy and backscattered electron diffraction( EBSD). The results show that the rheological stress of super alloy GH4698 increases with the decreasing of deformation temperature and the acceleration of strain rate,and super alloy GH4698 displays a better hot working behavior under the deformation temperature of 1000-1200 ℃ and the strain rate of 0. 01-0. 05 s^-1. Furthermore,in high and low power dissipation rate regions,as the power dissipation rate increases,the percentage of dynamic recrystallization increases,the size of average recrystallization grain increases,and the fraction of large angle grain boundary increases.

关 键 词：GH4698高温合金 热压缩 本构方程 热加工图 流变行为 微观组织演变 

分 类 号：TG3[金属学及工艺—金属压力加工]