The influence of the concentration of nonmetals in lithium on reactions with the alloy V-1 Si-3 Ti

Reactions between the vanadium-base alloy V-1 Si-3 Ti and lithium were studied at 550 degrees C in a forced convection loop made of stabilized austenitic stainless steel. Preheating the lithium in contact with a titanium sponge reduced the nitrogen and carbon levels below 100 wppm. In spite of the low concentrations of nonmetallic elements, the vanadium alloy picked up these contaminants, producing a hardened surface layer. Nitrogen concentrations in the range of 10 to 70 wppm significantly influenced the dissolution rate of the solid alloy Carbon uptake did not reach these levels. Surfaces of the alloy remained unprotected at the lowest nitrogen levels in the lithium. At higher contents, a protecting compound was detected at the surface of the alloy, reducing the dissolution rare during the corrosion test. Dissolution of vanadium and the minor alloying elements became evident when nitrogen concentration was increased further: Material losses from V-1 Si-3 Ti was only one tenth of that seen from either austenitic or ferritic stainless steels at the same temperature and flow velocity.