Study on the salt thermal corrosion behavior of MCrAlY at 700 °C

Abstract This study conducted thermal salt corrosion tests at 700 °C on five MCrAlY materials, analyzing various aspects such as surface morphology, corrosion products, cross-sectional corrosion characteristics, and weight loss to investigate the influence of fundamental elements like Co, Cr, and Al on sulfur-containing corrosion at this temperature. The results indicate that at 700 °C, the primary corrosion products are chromium oxide and aluminum oxide, with a minor formation of spinel. Corrosion manifests as a mesh-like structure of aluminum oxide that penetrates deeper into the material, often accompanied by the formation of chromium sulfide in its vicinity. Both cobalt and chromium are identified as beneficial elements for resisting thermal salt corrosion; notably, chromium demonstrates a superior enhancement effect against thermal salt corrosion at 700 °C compared to cobalt.