Corrosion rate and downstream effect in liquid metal systems

Results of experiments performed, especially of runs 1.10 and 1.12 have been evaluated with respect to the downstream effect in isothermal test sections in sodium at 1000 K. It is evident that there is not dependence of the selective Ni loss on position. This loss will be reduced considerably with high Ni concentration in sodium. The downstream function is influenced by different causes for short and extended exposure periods. Up to 400h Cr, together with impurities in sodium dominates the downstream effect. After longer exposure periods the steel surface will become equilibrated with respect to sodium conditions and the downstream effect will be dominated by elemental dissolution, essentially of Fe and saturation of dissolved elements in sodium. (author)