About this Abstract |
Meeting |
Materials Science & Technology 2020
|
Symposium
|
Computation Assisted Materials Development for Improved Corrosion Resistance
|
Presentation Title |
High Temperature Oxidation Lifetime Modeling of FeCr and NiCr Foils in Water Vapor |
Author(s) |
Marie Romedenne, Rishi Pillai, Sebastien Dryepondt, Bruce Pint |
On-Site Speaker (Planned) |
Marie Romedenne |
Abstract Scope |
Fe-based alloys are typically employed in heat exchanger components for combined heat and power generation systems. However, operating temperatures above 650 °C are desired to improve efficiency of these applications requiring the use of Ni-based alloys (e.g. alloy 625), which typically form a protective Cr2O3 scale. The ability to maintain formation of a protective Cr2O3 scale depends on an interplay of different processes (loss in wall thickness, subsurface Cr depletion, Cr2O3 volatilization). Foil specimens of Fe- and Ni-based alloys were oxidized in dry and wet air for up to 30,000 h at 650, 700 and 800 °C. Recuperator foils exposed for up to 100,000 h at about 650 °C in real engine conditions were also analyzed. The impact of composition, temperature and gas flow rates on Cr depletion and loss of wall thickness of the foils will be discussed with an oxidation kinetics model and coupled thermodynamic-kinetic diffusion calculations. |