U720Li镍基高温合金不同失稳判据的热加工图  

A Comparative Study of Various Flow Instability Criteria in Processing Map of Superalloy U720Li

作　　者：周舸[1] 韩寅奔[1] 曲敬龙[2] 丁桦[1] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110819 [2]钢铁研究总院高温材料研究所,北京100081

出　　处：《东北大学学报（自然科学版）》2012年第5期702-706,共5页Journal of Northeastern University(Natural Science)

基　　金：国家重点基础研究发展计划项目(2010CB631203)

摘　　要：在Gleeble-1500D热模拟试验机上对U720Li镍基高温合金进行高温压缩模拟试验.在Gegel提出的动态材料模型（DMM）概念的基础上,分别对Prasad,Gegel,Malas,Murthy,Semiatin几种不同的失稳判据进行综合分析与比较,并结合该合金在高温压缩变形过程中的显微组织演变规律得出以下结论：在温度为950~1 050℃,应变速率为5×10-4~10-1s-1的区域U720Li合金功率耗散率值均大于40%,并且在此区域内变形时该合金没有出现流变失稳现象.因此,该合金在此区域内适合成形加工.Hot compression tests of U720Li nickel base superalloy were conducted on a Gleeble-1500D thermal simulating tester.Based on DMM（dynamic material modeling） which proposed by Gegel,different types of instability criteria of Prasad,Gegel,Malas,Murthy,Semiatin were compared and the physical significance of parameters was analyzed.Meanwhile,the processing maps with different instability criteria were obtained.The results showed that the instability does not occur when average power dissipation rate is larger than 40% in the temperature range of 950~1 050 ℃ and strain rate range of 5×10-4~10-1 s-1.The deformation condition is appropriate for the processing deformation of superalloy U720Li.

关 键 词：U720Li镍基高温合金 热压缩实验 流变失稳准则 加工图 动态再结晶 

分 类 号：TG335.58[金属学及工艺—金属压力加工]