The study on kinetics of metadynamic recrystallisation of a Nb-V microalloyed non-quenched and tempered steel

摘要

The metadynamic recrystallisation (MDRX) behaviour of a Nb-V microalloyed non-quenched and tempered steel was investigated by isothermal hot compression tests on Gleeble-1500 thermal-mechanical simulator. Compression tests were performed using double hit schedules at temperatures of 1,273-1,423 K, strain rates of 0.01-5 s~(?1), initial grain sizes of 92-149 μm and inter-pass time of 0.5-10 s. The effects of deformation parameters, including deformation temperature, strain rate, initial grain size and inter-pass time, on MDRX softening fraction were analysed. The experimental results show that MDRX softening fraction increases with the increase of deformation temperature, strain rate and inter-pass time, while it decreases with the increase of initial grain size. Based on the experimental results, the kinetic model of MDRX for the tested steel was established. A good agreement between the experimental and predicted MDRX softening fraction indicates that the established kinetic model can precisely predict the MDRX softening fraction for the tested steel.