Conventional cold-rolling and annealing of 0.06%C steel

This paper demonstrated the ability to obtain an ultrafine-grained microstructure in 0.06%C steel via a simple process of cold-rolling and annealing, without the need for a severe plastic deformation process. A dual-phase ferrite-martensite starting microstructure was cold-rolled by 75% reduction in thickness and subsequently annealed at various temperatures from 400°C to 700°C for 30 min. The microstructures, as well as the microhardness and tensile strength properties, were evaluated by metallographic analyses and mechanical tests, respectively. The results showed that the specimen annealed at an intermediate temperature of 500°C exhibited excellent mechanical properties when compared to other annealing temperatures, as well as the as-received specimen.