Abstract:To clarify the high temperature flow stress behavior and microstructures evolution of a V-5Cr-5Ti (mass fraction, %) alloy, the isothermal hot compression tests were conducted in the temperature range of 1423–1573 K with strain rates of 0.01, 0.1, and 1 s^-1. The results show that the measured flow stress should be revised by friction and the calculated values of friction coefficient m are in the range of 0.45-0.56. Arrhenius-type constitutive equation was developed by regression analysis. The comparison between the experimental and predicted flow stress shows that the R² and the average absolute relative error (AARE) are 0.948 and 5.44%, respectively. The measured apparent activation energy Q_a is in the range of 540–890 kJ/mol. Both dis-continuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) mechanisms are observed in the deformed alloy, but dynamic recovery (DRV) is the dominant softening mechanism up to a true strain of 1.5.

Key words: V-5Cr-5Ti alloy; constitutive model; flow stress; dynamic recrystallization