About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
High Temperature Oxidation of Metals and Ceramics
|
Presentation Title |
Material Compatibility in Supercritical CO2 at 450°-650°C |
Author(s) |
Bruce A. Pint, Rishi Pillai, Michael Lance, James Keiser |
On-Site Speaker (Planned) |
Bruce A. Pint |
Abstract Scope |
Direct-fired supercritical CO2 (sCO2) power cycles are being commercialized to revolutionize fossil energy as a low-emission power source. To lower the cost of this technology, less expensive steels are needed in the lower temperature segments of the cycle. However, there are concerns about internal carburization of steels in this environment. In addition to 9-12%Cr ferritic-martensitic (FM) steels and conventional austenitic stainless steels (SS), additional candidates are being evaluated including advanced austenitic steels, high Fe content Ni-based alloys and protective coatings. A consistent observation is that thin, protective Cr-rich oxides appear to prevent C ingress and the associated room temperature embrittlement. However, when Fe-rich oxides form, C ingress occurs with rates dependent on the exposure temperature. The C diffusion profiles in FM and SS specimens are being quantified at 550°-650°C in order to validate a predictive model for these alloys and determine a maximum use temperature for this application. |