Effect of Strain Rate on Hot Deformation Behavior of Ti40 Burn-resistant Ti Alloy As-cast

The hot compression test of as-cast Ti40 alloy was carried out at the temperature range of 950 ℃～1100 ℃ and the strain rate range of 0.001 s-1～1.0 s-1 by a hot working simulator,and the effects of strain rate on flow stress and deformed microstructure of the alloy were studied.The results show that the flow stress increases with the increase of strain rate,and the true stress-true strain curves at different temperature and strain rates are stable-state.The lower the temperature,the lower the strain rate of dynamic recrystallization beginning.The volume fraction and average size of dynamic recrystallization grain increase with the decrease of strain rate.The degree of dynamic recrystallization is lower,and the maximum volume fraction is only about 20%.The average size of dynamic recrystallization grain is between 19.2 μm and 47.0 μm.Considering reducing energy consumption,improving workability and other aspects,the preferable strain rate should be below 0.1 s-1 at 950 ℃～1000 ℃.The preferable strain rate should be below 1.0 s-1 at 1050 ℃.The preferable strain rate should be at the range of 1.0 s-1 ～0.001 s-1 at 1100 ℃.