Le vingt-septième webinaire de l’association a été animé par Stéphane Gossé de l’Institut des Sciences Appliquées et de la Simulation pour les énergies bas carbone (Université Paris-Saclay, CEA). Ce webinaire porte sur la modélisation thermodynamique de la solubilité de quelques éléments d’alliage dans les caloporteurs métalliques.

Liquid metals and their alloys – particularly lead, lead-bismuth eutectic (LBE) – are fluid candidates for the primary or intermediary circuit of generation IV nuclear fast reactors (Lead-Cooled Fast Reactors) and accelerator driven transmutation systems (ADS).

As coolant materials, these liquid alloys exhibit numerous thermohydraulic and neutronic properties as well as inherent safety. However, the compatibility of these liquid alloys with the alloys of structural materials is a key point regarding corrosion.

To address this problem, the thermodynamic properties of alloying elements of iron-based alloys have been investigated using the Calphad method. The assessment of the solubilities and chemical activities of these minor elements in iron-based alloys (Co-Mn-Mo-Si) are a useful tool to predict their resistance to corrosion under lead (Figure 1) and LBE environments. In particular, these data are essential to support the study of kinetic mechanisms and transport phenomena in the circuits.