置氢Ti65钛合金高温流变行为和热加工性能  

High temperature rheological behavior and hot processing properties on hydrogenated Ti65 titanium alloy

作　　者：邵光保 胡进[2] 占克勤 席国庆 田壵 左培 邓磊[2] 李文彬[2] Shao Guangbao;Hu Jin;Zhan Keqin;Xi Guoqing;Tian Zhuang;Zuo Pei;Deng Lei;Li Wenbin(Hubei Tri-Ring Forging Co.,Ltd.,Xiangyang 441700,China;State Key Laboratory of Material Processing and Die and Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]湖北三环锻造有限公司,湖北襄阳441700 [2]华中科技大学材料成形与模具技术全国重点实验室,湖北武汉430074

出　　处：《锻压技术》2023年第8期253-260,共8页Forging & Stamping Technology

基　　金：湖北省重点研发计划(2020BAB040)。

摘　　要：Ti65钛合金具有优良的高温强度、热稳定性与抗蠕变性能,但其热成形温度高、变形抗力大。热氢处理作为一种钛合金高温增塑工艺,可以显著降低Ti65钛合金高温成形时的变形抗力,改善其热加工性能。为了研究置氢量对Ti65钛合金高温流变行为和热加工性能的影响,探究Ti65钛合金最佳置氢量和成形工艺窗口,对不同置氢量下的Ti65钛合金试样进行热压缩实验。结果表明,置氢Ti65钛合金在790~940℃温度范围内变形时,最佳置氢量(质量分数)为0.25%,与未置氢钛合金相比,峰值应力的降幅约为66.8%。基于真应力-真应变曲线数据,建立了0.25%置氢量时Ti65钛合金的Arrhenius本构方程,以及真应变为0.2、0.4和0.6条件下的热加工图。研究发现,Ti65钛合金在840~880℃、应变速率大于0.01 s^(-1)区域附近变形时,出现失稳现象,随着应变的增大,失稳区域收缩;而在790~840℃、应变速率为0.01~1 s^(-1)区域内变形时,具备良好的热加工性能。Ti65 titanium alloy has excellent high-temperature strength,hot stability and creep resistance,but its hot forming temperature is high and deformation resistance is large.As a high-temperature plasticizing process of titanium alloy,hot hydrogen treatment can significantly reduce the deformation resistance of Ti65 titanium alloy during high-temperature forming and improve its hot processing properties.Therefore,in order to study the influence of hydrogen content on the high-temperature rheological behavior and hot processing properties of Ti65 titanium alloy and explore the optimal hydrogen content and the forming process windows of Ti65 titanium alloy,hot compression experiments were carried out on Ti65 titanium alloy samples under different hydrogen contents.The results show that when hydrogenated Ti65 titanium alloy is deformed at the temperature range of 790-940℃,the optimal hydrogen content(mass fraction)is 0.25%,and the peak stress decreases by about 66.8%compared with the non-hydrogenated titanium alloy.Based on the true stress-true strain curve data,the Arrhenius constitutive equation of Ti65 titanium alloy with hydrogen content of 0.25%was established,and the hot processing maps of Ti65 titanium alloy under the conditions of the true strains of 0.2,0.4 and 0.6 were also established.The research finds that when Ti65 titanium alloy is deformed at the temperature of 840-880℃and the strain rate of greater than 0.01 s^(-1),the instability phenomenon occurs,and with increasing of the strain,the unstable region shrinks,while deformed at the temperature of 790-840℃and the strain rate of 0.01-1 s^(-1),it has good hot processing properties.

关 键 词：置氢Ti65钛合金 流变行为 本构方程 热加工图 置氢量 

分 类 号：TG316[金属学及工艺—金属压力加工]