A flat specimen corrosion cell for molten solids

Large interest is recently demonstrated by both scientific and industrial world on the corrosion behaviour of metals in contact with molten metals and salts, mainly caused by possible applications as heat-exchange liquids in Generation IV nuclear reactors. The operating conditions of these fluids are characterised by high temperatures and a strong interaction with the environment and the cell's building materials; moreover, the solid status at ambient temperature of the working 'liquid' makes the design of a standard test cell more difficult than the equivalent in aqueous media. In this work is presented a flat specimen cell for corrosion testing that uses the same geometry of similar cells for ambient temperature and the use of different building materials is discussed. The operation of the system is described, with specific attention to the insertion/rescue of the electrodes from the hot liquid: a part is dedicated to the meaning of a reference electrode in molten lead and different options are proposed and tested. Finally drawings and pictures of the test system are presented together with results from 300 series stainless steel analysis. The result of this work will then be applied in a standard product available from our lab while the scientific work will continue on testing references and other electrodes usable in this environment. (authors)