Exposure Tests of Different Materials in Liquid Lead for LFRs: Effect of the Dissolved Oxygen on Corrosion

Corrosion studies in high-temperature liquid Pb of conventional materials such as Fe–Cr and Fe–Cr–Ni steels for LFRs have demonstrated that they are prone to corrode affecting their structural integrity. Corrosion is minimized by using oxygen in Pb to form a protective Fe–Cr oxide layer on steels, but its protectiveness works well only up to 450–480 °C limiting their applicability in LFRs. The present work shows preliminary corrosion results of alternative materials (Ni alloys, FeCrAl ODS, Zr and Mo alloys, and SiC) for potential use in Pb, obtained by ENEA and Westinghouse Electric Company. Tests were performed in static Pb at 550 and 750 °C and different oxygen concentrations. The results demonstrated the potential availability in Pb of some of these materials and confirmed the key influence of oxygen on corrosion, imposing oxygen control in Pb coolant to prevent critical damage of materials. About oxygen control, some ENEA activities will be illustrated.