V-5Cr-5Ti合金的热变形行为及加工图  

Hot Deformation Behavior and Processing Map of V-5Cr-5Ti Alloy

作　　者：李增德[1] 林晨光[1] 崔舜[1] 

机构地区：[1]北京有色金属研究总院粉末冶金及特种材料研究所,北京100088

出　　处：《稀有金属》2015年第3期207-213,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51101021)资助

摘　　要：采用Gleeble-1500热模拟试验机对V-5Cr-5Ti合金进行了热模拟压缩试验。研究了V-5Cr-5Ti合金在变形温度为1373~1493 K、应变速率为0.1~30.0 s-1工艺条件下的流变行为,建立了合金高温变形的流变应力模型和加工图,并观察了合金变形后的金相组织。研究结果表明：流变应力和峰值应变随变形温度的降低和应变速率的提高而增大。以热模拟压缩试验为基础,通过对真应力-应变曲线的分析与计算得到了V-5Cr-5Ti合金的热变形激活能Q值为468.25 k J·mol-1,建立了V-5Cr-5Ti合金高温变形的流变应力模型。同时,建立了描述V-5Cr-5Ti合金热加工性能的热加工图,其由3部分组成,即Ⅰ变形安全区,Ⅱ变形安全区以及流变失稳区,其中流变失稳区呈对角线连续分布。在绘制、分析V-5Cr-5Ti合金的热加工图的基础上,结合组织分析得出,V-5Cr-5Ti合金最适合在Ⅱ变形安全区内采用液压机进行变形加工。The flow stress features of V-5Cr-5Ti alloy were studied by isothermal compression of cylindrical specimen in the temperature range of 1373 - 1493 K and strain rate range of 0.1 - 30.0 s-i with Gleeble-1500 simulated machine. The high temperature deformation constitutive equations and processing map were established, furthermore, the metallographic structures were investigated after deforma- tion. The results showed that the flow stress and steady strain increased with the deformation temperature decreasing and strain rate in- creasing. Based on the isothermal compression experiment, the thermal deformation activation energy （Q） was obtained as 468.25 kJ·mol-1 by analyzing and calculating the curves of true-stress and true-stain. The flow stress model of hot deformation V-SCr-STi alloy was constructed. Meanwhile, the processing map of high temperature deformation of V-SCr-STi alloy was established. The map consisted of three parts, including deformation region I, deformation region lI and flow instability region, and the flow instability region was diago- nally continuous distribution. Based on drawing and analyzing the thermal processing map of V-5Cr-5Ti alloy and the analysis of the struc- ture, the most suitable deformation method for V-5Cr-5Ti alloy was the deformation in deformation region Ⅱ using hydraulic machine.

关 键 词：V-5Cr-5Ti合金 热模拟试验 流动应力模型 热加工图 

分 类 号：TG146.4[一般工业技术—材料科学与工程]