Influence of solution treatment on the microstructure and crystallographic texture of cold rolled and recrystallised low carbon steel

Abstract

The effects of solution treatment on the texture and microstructure of cold rolled (e = 80 %) and recrystallised (T = 650 °C, salt bath) low carbon steel (mass content of 0.032 % C) were studied using both specimens having a maximum amount of carbon in solution and specimens in the as-hot-rolled state. For the investigations X-ray texture measurements and TEM observations were performed. Deformation was more inhomogeneous in specimens with carbon in solution. In such specimens a strong tendency to the formation of shear bands was observed at plastic strains in excess of 50 %. The specimens with little carbon in solution showed only few shear bands. Increasing contents of carbon in solution led to a degradation of the orientation density of the typical cold rolling texture components. This was attributed to the inhomogeneity of deformation, e.g. the formation of shear bands. The highest tendency to shear band formation was observed in {111} oriented grains. The development of shear bands in the deformation microstructure was interpreted in terms of Taylor theory. The {111} recrystallisation texture of samples with carbon in solution was weaker than in conventionally prepared samples. This observation was explained in terms of random nucleation in the inhomogeneously deformed microstructure and solute drag effects.