【摘要】 Ti-10V-2Fe-3Al钛合金热变形试件经α+β两相区固溶后，在其局部区域观察到了在单相β相区加热后才会出现的粗大β晶粒，表明该局部区域内的晶粒发生了异常长大，宏观组织上也表现为异常粗晶。通过热压缩试验系统研究了Ti-10V-2Fe-3Al钛合金的动态再结晶（DRX）行为，建立了β晶粒的DRX模型，明确了DRX特征与异常粗晶形成的定量关联规律，并在此基础上搭建了数值模拟平台，实现了异常粗晶分布的可视化预测。结果表明，变形温度的升高和应变速率的降低导致DRX晶粒尺寸(d_DRX)和再结晶体积分数(X_DRX)的增大。在低变形温度和高应变速率下，适中的X_DRX和较小的d_DRX使其在固溶后宏、微观组织均表现出了异常粗晶。然而，动态再结晶程度过于充足或不足均无法产生异常粗晶，表明异常粗晶是在适中的动态再结晶程度下的固溶产物。根据流变曲线与微观组织统计结果，构建了动态再结晶动力学量化模型和动态再结晶晶粒尺寸模型，并确立以再结晶晶粒尺寸(d_DRX)和再结晶体积分数(X_DRX)为关键参量的异常粗晶形成的量化判据模型，即，d_DRX≤2.60μm,72.5%≤X_DRX≤87.9%。通过集成粗晶判据子程序，利用DEFORM-3D有限元模拟软件分别模拟计算了圆柱形试样的等温热压缩过程及工字形件模锻成形过程，实现了宏观异常粗晶分布的可视化预测。试验结果与模拟结果之间具有良好的一致性，表明宏观异常粗晶与微观DRX之间的强相关性。更多还原

【Abstract】 After the hot deformation sample of Ti-10V-2Fe-3Al alloy was treated by solid solution in the α+β two-phase region, the coarse β grains that often appeared in the β single phase region were observed in the local region, indicating that the abnormal grain growth occurred in the local microstructural region, and the macrostructure also showed abnormally coarse grains（ACGs）. The dynamic recrystallization（DRX） behavior of Ti-10V-2Fe-3Al titanium alloy was systematically investigated through hot compression tests on the Gleeble-3800 system. The DRX model of β grains was established, and the quantitative correlation between DRX characteristics and the appearance of ACG was clarified. Based on these results, a numerical simulation platform was developed to realize the visual prediction of ACG distribution. The results show that the increase of deformation temperature and the decrease of strain rate both contribute to a significant increase in the grain size(d_DRX) and volume fraction(X_DRX) of DRXed grains. However, the proper X_DRX and smaller d_DRX at low deformation temperature and high strain rate make the macro and microstructure show ACGs after solid solution. Interestingly, if the DRX degree is excessive or insufficient, ACGs cannot be produced, indicating that ACGs are solid solution products based on the appropriate DRX degree. According to the flow curves and statistical results of microstructure, the quantitative model of DRX kinetics and DRX grain size model were constructed, and the quantitative criterion model that is related to the formation of ACG with grain size(d_DRX) and volume fraction(X_DRX) of DRXed grains as the key parameters was established, i. e., d_DRX≤2.60 μm, 72.5%≤X_DRX≤87.9%. By integrating the subroutine of coarse grain criterion, the isothermal compression process of cylindrical samples and the actual die forging process of H-shaped parts were simulated by DEFORM-3D software of finite element（FE）, respectively, and the visual prediction of the distribution of macroscopic ACGs was realized. There is a good consistency between the tested results and the simulated results, indicating a strong correlation between macroscopic ACGs and microscopic DRX.更多还原