Mechanical properties of a cold-rolled annealed HSLA steel

Hot rolled strips of an HSLA steel containing niobium and vanadium were cold rolled in the range 15 to 80% and annealed for 1 h at various temperatures from 400 to 700 ° C. The response to the amount of deformation and annealing temperature were studied in terms of changes in its hardness, tensile strength and ductility. Hardness and strength were observed to increase while ductility decreased with the amount of deformation. Although annealing of the steel up to 500 ° C did not show significant changes in its mechanical properties, a sharp decrease in hardness and strength and improvement in ductility were observed on annealing the steel at temperatures greater than or equal to 600 ° C. Microstructural studies showed complete recrystallization in the samples subjected to 60% deformation followed by annealing at 600 ° C.