# High-Temperature Performance of Alloy 800H UNS N08810 in Industrial Applications
Introduction to Alloy 800H UNS N08810
Alloy 800H (UNS N08810) is a nickel-iron-chromium alloy designed for high-temperature applications. This material offers exceptional resistance to oxidation and carburization, making it a preferred choice for industries operating in extreme thermal conditions.
Key Properties of Alloy 800H
The outstanding performance of Alloy 800H stems from its carefully balanced chemical composition and microstructure:
- High nickel content (30-35%) provides excellent resistance to oxidation and carburization
- Chromium content (19-23%) enhances corrosion resistance
- Controlled carbon content (0.05-0.10%) ensures optimal high-temperature strength
- Aluminum and titanium additions contribute to creep resistance
High-Temperature Capabilities
Alloy 800H demonstrates remarkable stability at elevated temperatures:
| Temperature Range | Performance Characteristics |
|---|---|
| 600-900°C (1112-1652°F) | Excellent oxidation resistance and mechanical strength |
| 900-1100°C (1652-2012°F) | Maintains structural integrity with controlled creep |
| Above 1100°C (2012°F) | Limited use due to gradual strength reduction |
Industrial Applications
Petrochemical Industry
Alloy 800H is extensively used in steam methane reformers, pyrolysis furnaces, and other high-temperature processing equipment where resistance to carburization and thermal cycling is critical.
Power Generation
The alloy finds application in superheater and reheater tubing, heat exchangers, and other components in fossil fuel and nuclear power plants that require long-term stability at elevated temperatures.
Heat Treatment Equipment
Furnace components such as radiant tubes, muffles, and retorts benefit from Alloy 800H’s ability to withstand continuous exposure to high temperatures while maintaining dimensional stability.
Comparison with Similar Alloys
While Alloy 800H shares some characteristics with other high-temperature alloys, it offers distinct advantages:
Keyword: Alloy 800H UNS N08810
- vs. 304/316 Stainless: Superior creep resistance and high-temperature strength
- vs. Alloy 600: Better resistance to carburization and oxidation
- vs. Alloy 800HT: Similar composition but with tighter controls on carbon and grain size
Fabrication Considerations
Working with Alloy 800H requires attention to specific processing parameters:
- Hot working should be performed between 2100°F (1149°C) and 2250°F (1232°C)
- Cold working requires intermediate annealing to maintain ductility
- Welding should be performed using matching filler metals with proper preheat and post-weld heat treatment
Conclusion
Alloy 800H UNS N08810 continues to be a material of choice for demanding high-temperature applications across multiple industries. Its balanced combination of oxidation resistance, creep strength, and fabricability