EFFECTS OF THERMOMECHANICAL TREATMENTS ON THE TRANSFORMATION KINETICSOF TITANIUM-ALLOYS - EXPERIMENTAL-STUDY AND NUMERICAL-CALCULATION

The studies realized show that a plastic deformation modifies the kine tics of the transformation beta-->alpha of the beta-Cez alloy. A shift of the TTT curves towards shorter times is observed for transformatio n temperatures higher than 750 degrees C. However, the kinetics are sl owed down for lower transformation temperatures. The amplitude of the effects is linked to deformation ratios and the deformation temperatur e. The quantitative microstructural study shows that the nucleation ki netics of beta-->alpha(GB) is accelerated, In addition, a calculation hiodel of the evolution of the transformation kinetics beta-->alpha(GB )+alpha(WGB) and beta-->alpha(WI) during continuous cooling is present ed.