Effects of mechanical stress on high temperature corrosion in molten salt

Abstract

Corrosion of molten salt thermal energy storage system containment materials is an important factor for system lifetime. To date there is a limited volume of work on the effects of mechanical stress on high temperature corrosion behaviour in molten salts. This study presents a method for investigating the effects of mechanical stress on the high temperature corrosion behaviour in Na2CO3/NaCl and Na2SO4/NaCl eutectic salts. Comparison of the results indicated stress resulted in a greater level of corrosion. In Na2SO4/NaCl the stress resulted in oxidation through the entire metal sample. A possible mechanism for this is inward sulphidation via grain boundaries. Future detailed work should be performed to further characterise and quantify the effects of stress on high temperature corrosion in molten salt.