Study of the corrosion characteristics of 304 and 316L stainless steel in the static liquid lithium

Abstract

• Corrosion behavior of 316L SS and 304 SS exposed to liquid Li at 600 K for 1320 h under Argon (Ar) atmosphere were investigated. • The corrosion characteristics of 316L SS and 304 SS was compared. • 316L SS was found to be more corrosion resistant in high-temperature liquid lithium than 304 SS. Liquid lithium (Li) is considered as the tritium breeder as well as a potential blanket coolant and/or plasma-facing material (PFM) in fusion devices, while steels are widely used as an important structural material in the fusion reactors. Investigation of corrosion behaviors of steels exposed to liquid Li is one of the keys to simultaneous apply Li and steels as potential PFM or blanket materials in the fusion devices. Hence, in this study, the corrosion behavior of 304 stainless steel (304 SS) and 316L stainless steel (316L SS) in static liquid Li, at 600 K, for 1320 h, under Argon (Ar) atmosphere is analyzed. After exposed to liquid Li, the mass loss of 304 SS is about 3.6 times more than that of 316L SS. And the corrosion depth rate of 316L SS and 304 SS is 0.71 μ m / a and 2.6 μ m / a , respectively. Both the materials have shown a non-uniform corrosion behavior. The Signs of grain boundary attack, pitting corrosion, and corrosion products formation, due to the selective dissolution of elements and chemical reactions are also observed. The percentage of corrosion product formation (i.e., carbides) on the surface of 304 SS, is higher than 316L SS. The hardness of two SS materials has a slightly increased after liquid Li exposure.