Ishwar Kapoor, Geoff West, Zushu Li; WMG, University of Warwick, Coventry
Yongjun Lan; Tata Steel, Coventry Technology Centre, Coventry
Arjan Rijkenberg; Tata Steel, 1970, CA IJmuiden
Vit Janik; WMG, University of Warwick, Coventry and Institute for Future Transport and Cities, Coventry University, Coventry
In this paper a new insight into fundamentals of static recrystallization, precipitation and their interaction during sub-critical annealing of three cold-rolled low-carbon microalloyed steel grades is presented. The grades under investigation are a base grade containing V as a microalloying element, a Ti þ grade containing Ti as microalloying element added into the base grade, and a Ti þ Mn þ grade containing additional Mn added into the Ti þ grade. The cold-rolled steels are sub-critically annealed inside a muffle furnace to simulate industrial continuous annealing parameters in order to investigate the interaction between recrystallization and precipitation across transient stages of the annealing process as a function of temperature and time. The Zener pinning of precipitates and solute drag force of Mn on the recrystallization process are calculated and compared with measured values obtained from experimental studies on the recrystallization kinetics. Results suggest that the recrystallization kinetics is fastest in the base grade. For the Ti þ grade, fine (<15 nm) (Ti,V)(C/N) particles retard the recrystallization kinetics. For the Tiþ and Ti þ Mn þ grades, solute drag effect of Mn solute atoms for dwell time longer than 2 min at annealing temperature of 800 �C is negligible.