Publications

Milestone Report: Effect of High Temperature CO₂ on Haynes 230 Alloy

Antoun, Bonnie R.; Kariya, Harumichi A.

The supercritical carbon dioxide (sCO₂) Brayton cycle is a promising candidate for future nuclear reactors due to its ability to improve power cycle energy conversion efficiency. The sCO₂ Brayton cycle can operate with an efficiency of 45-50% at operating temperatures of 550-700 C. One of the greatest hurdles currently faced by sCO₂ Brayton cycles is the extreme corrosivity of sCO₂. This affects the longevity of the power cycle and thus the levelized cost of electricity. Past studies have shown that sCO₂ corrosion occurs through the formation of metal carbonates, oxide layers, and carburization, and alloys with Cr, Mo and Ni generally exhibit less corrosion. While stainless steels may offer sufficient corrosion resistance at the lower range of temperatures seen by the sCO₂ Brayton cycles, more expensive alloys such as Inconel and Haynes are typically needed for the higher temperature regions. This study investigates the effects of corrosion on the Haynes 230 alloy, focusing on changes in the mechanical properties.