|About this Abstract
||Materials Science & Technology 2020
||High Temperature Corrosion and Degradation of Structural Materials
||Long-term Oxidation Behavior of Chromia-forming Alloys in High-temperature CO2 and Air
||Richard P. Oleksak, Casey S. Carney, Gordon R. Holcomb, Omer N. Dogan
|On-Site Speaker (Planned)
||Richard P. Oleksak
Future power systems require structural alloys that can survive long-term (>20 years) exposure to high-temperature CO2. Most studies have focused on relatively short exposures, and while this has improved mechanistic understanding of alloy oxidation in CO2, concerns remain for extrapolating short-term results to enable realistic lifetime predictions. In this work, several chromia-forming steels and Ni-based alloys were exposed in 500 h cycles to high purity CO2 at 700 °C and 1 atm for up to 10,000 h. For comparison, the alloys were also exposed to laboratory air at the same conditions. The exposed samples were characterized using a variety of techniques to assess for extent of oxidation and carburization. Most alloys performed well in pure CO2, forming thin, well-adhered chromia scales throughout the duration of the exposure. Surprisingly, the alloys that formed and maintained chromia scales showed no signs of carburization even after 10,000 h.