Microstructural characterization of a fine-grained ultra low carbon steel

Fine-grained ultra low carbon steel was prepared by equal-channel angular extrusion. The evolution of the microstructure and the deformation behavior were investigated as a function of the route. At room temperature the tensile strength of specimens prepared by route A is higher than that of the route C samples. The differences in microstructure between these two types of samples are discussed in terms of misorientation between the subgrains. The latter is correlated to the cumulated crystal rotations.