High throughput mapping of cementite phase transformation kinetics by space- and time-resolved high energy diffraction on compositionally gr

The aim of the present proposal is to determine the composition dependence of the influence of pro-eutectoid cementite on the austenite-to-ferrite phase transformation in steels. Depending on composition and cooling rate, significant differences of precipitation are observed. For hot rolled steels, this proeutectoid cementite can change dramatically phase transformations such as the ferrite/pearlite transition. For Advanced High Strength Steels, this precipitation plays a key role on the morphogenesis of the ferrite/austenite microstructure formed during inter-critical annealing. This investigation will use a recently designed combinatorial methodology relying on compositionally graded samples and time- and space-resolved in situ high energy X-ray diffraction, which provides quasi-continuous maps of phase transformation kinetics in compositional space. This methodology will be applied here to evaluate the coupling between pro-eutectoid cementite and the ferrite/pearlite transition.