Effects of H2O on corrosion kinetics and deuterium permeation of CLF-1 steel exposed to Li2ZrO3

The corrosion kinetics and deuterium permeation behavior of reduced activation ferritic/martensitic (RAFM) CLF-1 steel exposed to Li 2 ZrO 3 under high-temperature breeding blanket conditions were systematically investigated. The study revealed the corrosion kinetics of a bilayer corrosion structure that evolves with corrosion cycles, comprising a porous Fe-rich outer layer and a dense Cr-rich inner layer·H 2 O play a significant role in interfacial corrosion reactions, accelerating the degradation of the Fe-rich oxide through pore formation and delamination, resulting in enhanced deuterium permeation. Thermodynamic modeling confirmed that the interfacial reaction mechanism involves sequential structural transformations involving LiFeO 2 , Li 2 Fe 3 O 4 , Fe and LiCrO 2 phase. TEM reveals the dynamic microstructural evolution underlying the deterioration of the bilayer. A time-dependent corrosion model is proposed to elucidate the correlation between structural evolution and permeation resistance. With extended exposure, the Cr-rich LiCrO 2 phase dominates, acting as a passivating barrier that significantly impedes hydrogen isotope transport. Arrhenius analysis further substantiates the effectiveness of this evolving oxide structure in suppressing tritium permeation, highlighting the critical influence of H 2 O in corrosion-driven transport mechanisms.