在应变速率0.1~0.001 s^-1、变形温度730~880℃下对Ti-10V-2Cr-3Al钛合金进行热压缩试验,研究了该合金的热变形行为和显微组织;利用唯象Arrhenius方程中指数方程及双曲正弦方程描述流动应力与变形温度、应变速率之间的关系,构建了应变补偿修正的本构方程并进行了验证。结果表明:在试验条件下合金的真应力随着应变速率的增加或变形温度的降低而增大;当应变速率为0.01 s^-1时,在α+β相区(730,790℃)压缩后试验合金中出现球状和短棒状α相,软化机制为动态球化和动态再结晶,在β相区(820,880℃)压缩后出现再结晶β晶粒,软化机制为动态再结晶;当应变速率在0.1~0.05 s^-1和0.01~0.001 s^-1范围时,可分别使用修正后的指数方程和双曲正弦方程来描述试验合金的流变行为,流动应力预测值与试验值的平均相对误差为5.36%,这说明修正后的方程具有良好的预测能力。

Hot compression tests were carried out on Ti-10V-2Cr-3Al titanium alloy at the strain rate of 0.1-0.001 s^-1 and deformation temperature of 730-880 ℃, and the hot deformation behavior and microstructure of the alloy were studied. The exponential equation and hyperbolic sine equation in the phenomenological Arrhenius equation were used to describe the relationship between flow stresses and deformation temperatures and strain rates. The constitutive equation corrected by strain compensation was established and verified. The results show that the true stress of the alloy increased with increasing strain rate or decreasing deformation temperature under test conditions. At the strain rate of 0.01 s^-1, spherical and short rod-like α phases appeared in the test alloy after compression in the α+β phase region (730, 790 ℃), and the softening mechanism was dynamic spheroidization and dynamic recrystallization; recrystallized β grains appeared after compression in the β phase region (820, 880 ℃), and the softening mechanism was dynamic recrystallization. When the strain rate was in the range of 0.1-0.05 s^-1 and 0.01-0.001 s^-1, the flow behavior of the test alloy could be described by the corrected exponential equation and the corrected hyperbolic sine equation, respectively. The average relative error between the predicted flow stresses and the experimental flow stresses was 5.36%, indicating that the corrected equations had good predictive ability.