Corrosion Resistance of Metal during Heat Treatment of NaCl-Na2SO4 Waste Salt

In order to investigate the corrosion mechanism of waste salt thermochemical treatment and screen suitable metal materials for use in the reactor, several common alloy materials, including 316L, Inconel625, Incoloy825, C276 and TA2, were selected and subjected to a 20 h short-term corrosion tests at 800, 850 and 900 ℃ in 80% NaCl-20% Na2SO4 mixed salt. Results showed that Inconel625 could be used in the waste salt thermochemical treatment device. The Inconel625 alloy was subjected to a 10 d corrosion test. The corrosion products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy spectrum analysis (EDS). The main corrosion products were found to be NiO and Cr2O3. It was determined that the corrosion behavior followed the corrosion mechanism “oxidation activation theory” and the “acid-base melting model”.