Corrosion experiments on IN-RAFM steel in flowing lead-lithium for Indian LLCB TBM

Corrosion experiments were carried out in a pump driven loop, exposing IN-RAFM (India specific Reduced Activation Ferritic Martensitic) steel samples to lead-lithium, Pb-16Li. In this loop, flat and tensile samples, made of IN-RAFM steel were exposed to lead-lithium, flowing at ∼10 cm/s velocity and maintained at (465 ± 3)°C temperature. Three experiments were carried out, for different time durations, 1000 h, 2500 h and 5000 h. Samples were removed after each experiment and metallurgical investigations were carried out using SEM and SEM/EDX. Tensile strength and hardness measurements were also carried out and the results are discussed in this paper. Corrosion rate estimated from weight loss measurements was ∼44 μm/year up to 2500 h and it reduced to ∼31 μm/year after 5000 h exposure. Iron and chromium were found leaching from the samples. Hardness reduction was observed up to 40 μm after exposing to liquid metal for 5000 h. There is no significant reduction in tensile strength and % elongation after exposing the samples up to 5000 h to liquid metal.