Affinement des grains dans les aciers hypoeutectoides

Abstract

In this memory, we studied the refinement of the grains in a steel hypoeutectoide (0.19%C). We tried to apply several thermomechanical treatments to our samples in order to see the evolution of the size of the grains. The optical microscope, the Vickers microhardness, the electron microscope with sweeping and the diffraction of the X-rays were our means of analysis. Through this study, several microstructures and curves of hardness were presented, where we showed the conditions of the thermomechanical treatments which make it possible to give the finest size of the grains. We found that the larger the rate of hot deformation is and the shorter time of maintenance of annealing is plus the size of the grains is fine.