Effect of pearlite morphology on recrystallization behaviour in cold rolled high strength automotive steel sheets

Abstract

The present study is mainly focused on recrystallization behaviour and associated microstructure and texture evolution with the effect of second phase as pearlite. Two cold rolled sheets with 80% cold reduction consisted of coarse and fine pearlite bands along with ferrite. Cold rolling was followed by interrupted annealing at different soaking time to study the kinetics and recrystallization texture evolution. Results are analysed with the help of micro-Vickers hardness, microstructure and texture analysis through SEM and Electron Backscattered Diffraction (EBSD). Results clearly show the effect of pearlite band size on recrystallization kinetics and texture evolution. Faster recrystallization is observed for fine pearlite band compared to coarse band. Heterogeneous nucleation of grains took place at ferrite pearlite interface, grain boundaries of RD-ND orientations and within the deformed ferrite. Fragmentation and spherodization of pearlite lamellae takes place inside the colony of pearlite with increase in soaking time.