Abstract:Hot compressive deformation of Ti600 alloy after thermo hydrogen treatment (THT) was carried out within hydrogen content range of 0−0.5%, temperature range of 760−920 ℃ and strain rate range of 0.01−10 s⁻¹. The flow stress of Ti600 alloy after THT was obtained under hot deformation condition, and the influence of hydrogen on work-hardening rate (S*), strain energy density (U*), and deformation activation energy (Q) was analysed. The results show that the flow stress of Ti600 alloy decreases remarkably with the increase of hydrogen when the hydrogen content is less than 0.3%. Both S* and U* decrease with the increase of hydrogen when the hydrogen content is less than 0.3%, and when the hydrogen content is more than 0.3%, S* and U* increase with hydrogen addition. The value of Q decreases with the increase of strain at the same hydrogen content. The addition of small quantity of hydrogen leads to an increase of Q at small strain values, and when the strain reaches 0.6, the value of Q decreases gradually with the increase of hydrogen. When the hydrogen content is within the range of 0.1%−0.3%, the flow stress of Ti600 alloy is decreased when being deformed at the temperature range of 760−920 ℃.

Key words: Ti600 alloy; thermo hydrogen treatment; hot deformation; flow stress; activation energy