STATIC RECRYSTALLIZATION OF HOT DEFORMED AUSTENITE AND INDUCED PRECIPITATION KINETICS IN VANADIUM MICROALLOYED STEELS

Using torsional tests and applying the back extrapolation method the k inetics of the static recrystallization of hot deformed austenite has been studied in three microalloyed steels with different vanadium cont ents and this has been modelled at temperatures above and below the st atic recrystallization critical temperature (SRCT). The SRCT has been found to be a function of the strain, the austenite grain size and nat urally the microalloy contents, in this case N and V. A study has also been made of the kinetics of the precipitation induced by the strain and the precipitation-time-temperature (PTT) diagrams have been determ ined for the three steels. The no-recrystallization temperature (T(nr) ) has also been determined and the conclusion was reached that the dif ference between the T(nr) and SRCT is mainly due to the austenite grai n size, which is smaller in the determination of the T(nr) due to the successive recrystallizations which occur before precipitation takes p lace.