Corrosion and electrochemical investigations for stainless steels in molten Solar Salt: The influence of chloride impurity

The influence of chloride impurity on corrosion behavior of stainless steels (304, 316 L and 347 SS) was carried out in molten Solar Salt at 565°C. Static immersion and electrochemical polarization tests were carried out at 565°C. It was found that the corrosion rates of the studied steels obtained from both static immersion and EP tests significantly increase in Solar Salt with the presence of chloride impurity. The chloride enhances the aggressiveness of the molten Solar Salt at 565°C by producing oxidants, which aggravates the corrosion extent of the investigated steels. Moreover, the oxide scale formed in molten Solar Salt containing chloride impurity is prone to spall. The synergy effect of active oxidation and the spallation of the oxide scale dominates the accelerating corrosion process.