反应堆耐压壳体用Ti-5Al-3V-3Zr-0.7Cr合金的热变形行为  

Hot Deformation Behavior of Ti-5Al-3V-3Zr-0.7Cr Titanium Alloy as a Candidate Material for Pressure Hull of Fusion Reactor

作　　者：赵彬 赵永庆[2] 侯智敏[2] 罗媛媛[2] 张文[2] 张平祥[2] 吴金平[2] Zhao Bin;Zhao Yongqing;Hou Zhimin;Luo Yuanyuan;Zhang Wen;Zhang Pingxiang;Wu Jinping(State Key Laboratory of Solidification Process, Northwestern Polytechnical University, Xi’an 710072,China;Northwest Institute for Nonferrous Metal Research, Xi’an 710016,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西北有色金属研究院,陕西西安710016

出　　处：《稀有金属材料与工程》2019年第6期1872-1877,共6页Rare Metal Materials and Engineering

基　　金：陕西省重点科技创新团队计划项目(2016KCT-27);陕西省国际合作与交流项目(2016KW-060)

摘　　要：利用Gleeble-3800型热模拟试验机对经过三次真空自耗熔炼的Ti-5Al-3V-3Zr-0.7Cr(质量分数,%,下同)合金进行热模拟等温压缩实验,研究了在750~900℃及0.001~1 s^-1应变速率下的高温流变行为及再结晶行为。结果表明,在合金的高温变形过程中,流变曲线呈现出明显的先硬化后软化的流变行为特征,应变速率的降低或温度的升高都会使合金的流变应力降低;造成该合金流变软化的主要原因是动态再结晶。动态再结晶的临界应变与峰值应变之间成线性关系,随着温度和真应变增加,再结晶体积分数呈"S"型增加。在不同变形条件下建立了合金的热加工图,合金的最佳高温塑性变形参数为:750℃/0.001~0.01 s^-1和850~900℃/0.01~0.1 s^-1。The isothermal hot compression experiment of Ti-5Al-3V-3Zr-0.7Cr alloy melted by VAR melting three times was performed by Gleeble-3800 thermo-simulation machine. High-temperature deformation and recrystallization behaviors of the as-cast alloy were studied over a wide range of strain rate(0.001 to 1.0 s^-1) and temperature(750 to 900 °C). The results show that the flow curves for the current alloy firstly exhibits sharp peaks at low strain levels revealing pronounced work hardening, and then drops rapidly after peak stress presenting the soft characteristics. The flow stress decreases with decreasing the strain rate or increasing the temperature. Dynamic recrystallization(DRX) is the major softening mechanism. The relationship between the critical strain and the peak strain of DRX is linear.Based on the conventional recrystallized fraction curves, the recrystallized volume fraction grows as an "S" shape with the increasing the deformation temperature and the true strain. Processing maps were established under different deformation conditions, and the optimal condition for hot work on this material was determined to be 750 °C/0.001~0.01 s^-1 and 850~900 °C/0.01~0.1 s^-1.

关 键 词：钛合金 高温流变行为 再结晶行为 热加工图 

分 类 号：TG146.23[一般工业技术—材料科学与工程]