A Study of Corrosion and Mass Transfer Of Nickel by Molten Sodium Hydroxide^⋆ Available to Purchase

The usefulness of nickel as a container material for molten sodium hydroxide is severely hampered at high temperatures by the occurrence of corrosion and mass transfer whenever a temperature gradient is present in the system. Free convection studies at other laboratories and preliminary studies at the National Advisory Committee for Aeronautics Lewis laboratory showed that the amount of mass transfer is strongly affected by variables such as temperature level, temperature gradient, flow conditions, atmosphere and the chemical composition of both the caustic and the nickel. It was found that normal care in the control of these variables resulted in reproducibility of the order of 200 to 300 percent. A free convection test was developed which yielded results reliable to ±10 percent and made it possible to study the effects of the different variables and to investigate the effectiveness of additives. The relations between mass transfer rate and temperature gradient were established in the temperature range 1400 to 1600 degrees F. The effects of additions of a large variety of materials to the caustic were also studied.