REVIEW OF HAYNES® 282® ALLOY FOR SUPERCRITICAL CO₂ STRUCTURAL APPLICATIONS

In this paper, HAYNES® 282® alloy (282® alloy) properties, microstructure, high temperature oxidation resistance, weldability, and American Society of Mechanical Engineers (ASME) code case highlights are reviewed. The long term performance of high temperature, high strength, creep resistant alloys is critical to the success of supercritical carbon dioxide equipment. Several modern power generation technologies require alloys that can operate continuously at or above 700^oC. 282® alloy is a precipitation strengthened nickel based super alloy that meets these requirements. The results of 282® alloy research reviewed in this paper include long-term cyclic oxidation behavior in air and sCO₂, independent research and validation of 100k hour creep life, and successful welding of the alloy in the age hardened condition. The latter is critical for joining of hardened components (flanges, piping, heat exchanger internal, etc.) and field repair. Several highlights from the code case for this ASME-approved material are also presented.