A novel technique for developing bimodal grain size distributions in low carbon steels

In this study a new method is introduced to produce bimodal grain structures in low carbon steels. This method is based on cold rolling of dual-phase structures and appropriate annealing treatments. The difference in the recrystallization behaviour of ferrite and martensite yields a heterogeneous microstructure with a distribution of coarse and fine grains. These types of microstructures are of interest for optimizing the balance of strength and uniform elongation in ultrafine-grained low carbon steels.