Structural and textural aspects of deformation and recrystallization of low-carbon steels containing dispersions of Nb(CN)

Abstract

The effect of variation of second-phase particle size and spacing on the structure and crystallographic texture of two 80% cold-rolled and recrystallized low-carbon steels containing dispersions of Nb(CN) has been studied by a variety of techniques. Alloy compositions, based on Fe-0.5wt-%Mn, were chosen to give ∼ 0.12 and ∼ 0.18 vol.-%Nb(CN). The dispersions were produced by interphase precipitation. The behaviour of these materials was compared to that of a niobium-free steel. Parallel kinetic measurements had shown that the recrystallization rates of the two-phase steels could vary by a factor of ∼ 10⁶ with change of interparticle spacing over the range studied, the effect being mainly caused by change of the nucleation kinetics of recrystallized grains. In the present work a detailed investigation of the cold-worked materials showed that the changes in dispersion caused significant substructural changes which in turn caused textural variations. These factors were then responsible for causing the variation in nucleation kinetics of recrystallized grains. There was also a significant variation of recrystallized texture with change of second-phase dispersion.