Microstructural characterization and recrystallization kinetics modeling of annealing cold-rolled vanadium microalloyed HSLA steels

• Microstructural characterization during annealing of cold-rolled HSLA-V steels.
• Quantification of recrystallization kinetics using EBSD technique.
• Analysis of recrystallization kinetics using a modified JMAK model.
• Recrystallization follows one dimensional preferential growth in HSLA-V steels.

In this study, we investigated the microstructural evolution and recrystallization kinetics during the annealing of cold-rolled Vanadium microalloyed HSLA (denoted as HSLA-V) steels using both experimental characterization techniques and theoretical model analysis method. Our experimental results indicate that the recrystallization kinetics can be quantified with the evolution of volume fraction of recrystallization as a function of annealing time, and is strongly dependent on the processing parameters (i.e., cold-rolling reduction and annealing temperature) of the HSLA-V steels. Validated by experimental data, our physics-based model analysis revealed that the recrystallization process in the HSLA-V steels consisted of an early stage with both nucleation and grain growth processes and a later stage with grain growth only. Moreover, the growth of the recrystallized grains was found to follow one dimensional preferential growth mechanism, owing to the dispersed V(C,N) precipitates, in the HSLA-V steels. Consequently, our new analysis model is demonstrated to be useful to gain insights into the recrystallization kinetics in the annealed cold-rolled HSLA-V and even other microalloyed steels.