Corrosion and mechanical behavior of novel alumina forming steels in molten lead

• 3.5 wt.% al was sufficient to form protective oxides in stagnant lead at 550 and 650 °C with no reactive elements added. • No degradation in mechanical properties was observed in the alumina-forming developed steels after short-term (1000 h) high-temperature lead exposure tests. Further long-term studies would be necessary to confirm these results. • The proposed alloys outperformed the nuclear reactor candidate materials 316 L and T91 both in terms of oxidation resistance and in mechanical properties after short-term (1000 h) exposure to liquid lead. Three new multi-phase alumina-forming steels with compositions Fe-(10–14.5)Cr-(10–12)Ni-3.5Al (wt.%) were exposed to stagnant lead at 550 and 650 °C for up to 1000 h The experimental alloys formed stable and protective alumina (Al 2 O 3 ) layers at both temperatures, crucial for preventing lead penetration and material degradation. In contrast, 316 L and T91 steels, candidate materials for nuclear applications, showed significant oxidation and lead penetration, particularly at the higher temperature. The designed alloys retained their mechanical properties after exposure, with one of them even increasing yield strength due to phase transformations. The findings highlight the potential of these new alloys with no reactive elements and no thermomechanical treatments, to operate in environments with high-temperature liquid lead, such as Gen IV nuclear reactors or high-temperature concentrated solar power plants.