Effects of V and Nb on static recrystallisation of austenite and precipitate size in microalloyed steels

Recrystallisation and precipitation in two microalloyed steels, one with Nb and the other with V, have been studied. The Nb-steel displayed two plateaus on the curves of recrystallised fraction against time. The difference between activation energies allow to predict the efficiency of different precipitates to strengthen the austenite during hot rolling. RPTT diagrams showed the interaction between both phenomena. It is found that NbCN particles nucleate and grow faster than VCN, but the latter are smaller.