About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmental Degradation of Multiple Principal Component Materials
|
Presentation Title |
Flow and Steam Enhanced Degradation of Once Through Steam Generation Piping Steels |
Author(s) |
Kevin J. Hodder, Omnath Ekambaram, Saeid Dehghani, John A. Nychka, Basil Perdicakis, R. Sean Sanders |
On-Site Speaker (Planned) |
John A. Nychka |
Abstract Scope |
Once through steam generation (OTSG) piping operates under severe environmental conditions including high temperature, aqueous fluids with chemical additives (which may act as corrosive impurities), and high flow rates. The ability of piping steels in OTSGs to withstand such environmental conditions depends heavily on the combination, and synergistic effects, of the environmental conditions and the underlying chemistry and metallurgical structure of the steels of choice. This work describes various degradation mechanisms acting on industry supplied cutouts of piping from in service OTSGs, and results from a custom designed batch autoclave designed to recreate OTSGs conditions on a lab bench scale. Visual examination and materials characterization techniques (e.g., optical and electron microscopy with EDX, x-ray diffractometry, metallurgical microstructural analysis) were employed to elucidate the degradation mechanisms acting in various operating envelopes. Observed damage modes responsible for severe metal losses ranged from crevice corrosion, pitting corrosion, flow enhanced corrosion, and caustic attack. |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Temperature Materials, Environmental Effects, Iron and Steel |