摘要
利用Gleeble-3800热模拟试验机对新型高密度DT740合金进行轴向热压缩试验,研究该合金在变形温度950~1250℃、应变速率0.01~1 s-1条件下的热变形行为及组织演变规律,基于双曲正弦本构关系建立其本构方程并依据动态材料模型建立热加工图,分析讨论了不同区域内的高温变形特征,确定该合金最佳的热加工工艺参数。研究结果表明:DT740合金的流变曲线表现出典型的动态再结晶特征,其流变应力随变形温度的降低和应变速率的升高而增加;计算得到该合金的热变形激活能Q为546.87 k J·mol-1;确定了DT740合金最佳的锻造热加工温度范围为1150~1250℃,在此温度范围内合金的热加工性能最佳,可获得均匀、细小的完全动态再结晶组织,能量耗散率η值约为44%。
The axial thermal compression test of new high density DT740 alloy was carried out by using Gleeble-3800 thermal simulation machine.Hot deformation behavior and microstructure evolution of DT740 alloy were investigated at deformation temperature of 950-1250℃and strain rate of 0.01-1 s-1.Based on the hyperbolic sin constitutive relation,the constitutive equation of DT740 alloy was established.The hot processing map based on dynamic material model(DMM)was obtained and the high temperature deformation characteristics were analyzed and discussed in different regions.The best thermal processing parameters of DT740 alloy were determined.The results indicate that the rheological curve of DT740 alloy shows typical dynamic recrystallization characteristics,the flow stress increases with the decrease of deformation temperature and the increase of strain rate.The calculated hot deformation activation energy Q of DT740 alloy is 546.87 kJ·mol-1.The optimum forging temperature range for DT740 alloy is 1150-1250℃.In this temperature range,the alloy can obtain uniform,fine fully dynamic recrystallized grain can be obtained and the energy dissipation efficiency is about 44%.
作者
张胜
王春旭
姜庆伟
刘少尊
李建新
厉勇
ZHANG Sheng;WANG Chun-xu;JIANG Qing-wei;LIU Shao-zun;LI Jian-xin;LI Yong(School of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China;Institute of Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China;Technology Center,Fushun Special Steel Co.,Ltd.,Fushun 113000,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2019年第6期213-219,共7页
Journal of Plasticity Engineering
基金
国家重点研发计划资助项目(2016YFB0300104)
关键词
高密度DT740合金
热变形
本构方程
热加工图
high density DT740 alloy
hot deformation
constitutive equation
hot processing map
