Compatibility of 316L stainless steel with liquid and solid tritium breeding materials

Corrosion of 316L stainless steel in flowing 17Li-83Pb has been investigated at 400 and 4500C up to 3000 h exposures. At both temperatures, the steel develops a thick and porous ferrite layer, with an important nickel and chromium depletion. The influence on corrosion rate of temperature, time, microstructure of steel, alloy velocity and cold trap purification is presented and discussed. The compatibility of 316L stainless steel with γ-LiAlO2 ceramic has been studied in 500 h contact tests under vacuum at 600 and 7000C. A sulphidation of the contact surface, due to a sulphate impurity contained in the ceramic, has been shown. These characterization tests have led the ceramics supplier to improve this material by decreasing its sulphur content to 100-200 ppm. (orig.)