Corrosion of austenitic steel in leakage lithium

High-temperature lithium, which is used as the neutron source in the International Fusion Material Irradiation Facility, reacts with oxygen, nitrogen, and moisture in the atmosphere. We estimated which lithium compounds might be stable under environmental conditions by using chemical equilibrium calculations, then performed austenitic stainless steel corrosion tests with the selected lithium compounds. The lithium compounds (reagents) and a steel specimen were heated to 1120 K in an Al2O3 Tammann crucible. After the test, the steel specimen was cleaned with alcohol and water and then weighed and metallurgically examined. We found that the steel was significantly corroded in Li3N, LiOH, and Li2O2 environments. Because Li2O2 is not stable according to the chemical equilibrium calculations, corrosion by Li3N and LiOH needs to be considered in high-temperature lithium applications.