Hot Corrosion Monitoring of Waste Incineration Corrosion Processes Using Electrochemical Techniques

In order to evaluate the damage of molten salt mixtures in waste incineration environments, the alloy 625 was exposed to a molten KCl-ZnCl2 mixture at 650 °C for 200 hours. The corrosion process was monitored by electrochemical impedance spectroscopy (EIS). After exposure the corrosion products were analyzed by X-ray diffraction and SEM. Two different electrochemical impedance models were found to describe the electrochemical processes. In the early stages of corrosion the alloy developed a protective Cr2O3 scale which turned into a porous spinel oxide scale after 100 hours.