Should the oxygen source be considered in the initiation of KCl-induced high-temperature corrosion?

Abstract

Abstract The role of two oxygen sources, oxygen and water vapor, in the initiation of KCl-induced high-temperature corrosion was addressed by studying two high-alloyed commercial materials at 550 °C. The differentiation between the two oxygen sources was implemented with 18O-enriched water and 16O2. Based on the results, the solid-solid reaction between KCl(s) and the protective oxide on the alloy surface appeared to be more responsible for corrosion than the gas-solid reaction between KCl(g) and the protective oxide. Water was more involved in the abovementioned reactions than O2: 18O was the main oxygen isotope found in the formed surface oxides and intermediates.