Are NaCl and KCl equally corrosive on superheater materials of steam boilers?

► Solid NaCl and KCl show severe corrosivity on superheater steels. ► Some differences in corrosion behaviour between the two salts were observed. ► Sanicro 28 exhibited more internal degradation during exposure to NaCl than to KCl. ► Oxide formed through vaporisation of chlorides at lower temperatures with NaCl. ► For practical applications both salts are equally corrosive.