Particle in Ti-V-Nb
microalloyed steel and its effect on the growth of
austenite grain in HAZ were investiated by using carbon extraction replica technology and
welding thermal simlation.Experiment results and analysis show that large amount of small dispersed
Particle containing Ti,Nb and V exist in the steel,and those particles are very stable and can effectively inhibit austenite grain
coarsening during welding thermal
cycle;with the peak temperature of welding thermal cycle not higher than 1200℃,the particle dissolving and coarsening are very weak,thus the austenite grain coarsening rate is very slow,and the austenite grains size does not increase significantly with the increase of t_(8/5);with the the peak temperature of welding thermal cycle higher than 1250℃,the particle in HAZ are evidently dissolved and coarsened,the austenite grain coarsening rate is very slow,and the austenite grains coarsening rate increases,and the grain size increases significantly with the increase of t_(8/5) and T_m.