Comparative interaction of cold-worked versus annealed inconel 601 with molten carbonate salt at 450 °C

Abstract

The interaction between Inconel 601 and the eutectic mixture of Li2CO3+K2CO3+Na2CO3 at 450°C was investigated for thermal energy storage. Electron backscatter diffraction, optical microscopy, Volta potential, polarization and impedance measurements were used to compare the alloy behaviour in cold-worked and annealed conditions. Results showed that annealing leads to a lower corrosion rate accompanied by fewer areas of localised attack. Volta potential measurements confirmed the development of micro-anodic sites on the surface in cold-worked condition which provide driving force for localised attack. These sites were found responsible for relatively higher corrosion rate and formation of meta-stable pits.