EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Metal Dusting is a high temperature corrosion mechanism observed in industries handling carbonaceous gases. In the temperature range of 400 to 900°C, carbon-rich species of the gas decompose and carbon diffuses into the material, resulting in a catastrophic material degradation. The dissociation reactions are catalyzed by iron, nickel and cobalt. Iron and nickel are commonly used as base elements for parts exposed to conditions with high risk of metal dusting. Thus, these alloys need to be protected by alloying or coating strategies in order to ensure safe operation of the processing plants.
Alloying with the oxide formers chromium, aluminum and silicon is a common approach to prevent metal dusting. Hence, the performance of commercial alloys with high amounts of oxide formers under metal dusting conditions is of high interest for the affected industry. In this study, the formation of chromia and alumina scales and their protection properties against metal dusting of commercial Ni-based alloys is discussed. Alloy resistance is highly dependent on the aggressiveness of the test conditions. In order to establish a short and efficient testing method, exposure tests in highly aggressive gas mixtures at elevated pressure were performed.