|About this Abstract
||MS&T23: Materials Science & Technology
||High Temperature Corrosion and Degradation of Structural Materials
||Environmental Creep Behavior of Austenitic Steels in CO2
||Richard P. Oleksak, Kyle A. Rozman, Ímer N. Doğan
|On-Site Speaker (Planned)
||Richard P. Oleksak
Austenitic stainless steels are leading candidate materials for constructing supercritical CO2 power cycles. Due to a combination of high temperatures (>600░C), high fluid pressures (>20 MPa), and long anticipated component lifetimes (>20 years), creep will likely be a main form of degradation. CO2 can produce high corrosion rates for steels due to simultaneous oxidation and carburization, however the effect of these processes on creep performance is not well understood. Of particular concern are thin-walled components such as compact heat exchangers, which may be more susceptible to CO2-induced degradation. Herein we performed environmental creep testing of 347H and 309H steel of various thicknesses (0.5-2.0mm) in gaseous CO2 and air at 650░C. Decreases in rupture life and ductility were found in several cases, while the effect of thickness was complex. Characterization suggests that carburization plays an important role. Understanding/quantifying these effects will be important for material selection for sCO2 power cycles.