Corrosion Fatigue of 316L Stainless Steel in Hot LiOH Solution

The corrosion fatigue behavior of AISI 316L (UNS S31603) stainless steel was tested in concentrated aqueous lithium hydroxide solutions at elevated temperature. Fatigue tests were conducted in a 10 g LiOH/100cc H2O solution at 95°C at controlled electrochemical potentials. Experimental conditions met requirements of the aqueous Li salt blanket option for the international and European nuclear fusion reactor programs of the International Thermonuclear Experimental Reactor (ITER) and Next European Torus (NET). Results indicated 316L stainless steel was susceptible to corrosion fatigue in a narrow potential range of approximately 100 mV (vs SCE). Tests at lower or higher potentials (e.g., –80 and 200 mV), however, did not show susceptibility to corrosion fatigue cracking. Results were compared with the stress corrosion cracking behavior of 316L in the same environment.