Alloy 800H: High-Performance Material for Elevated Temperature Applications
Alloy 800H is a nickel-iron-chromium alloy designed for high-temperature and high-stress environments. It offers excellent strength, resistance to oxidation, and superior thermal stability, making it ideal for demanding industrial applications.
Composition and Features of Alloy 800H
Elemental Composition
| Element | Typical Percentage | Role and Contribution |
|---|---|---|
| Nickel (Ni) | 30–35% | Provides high-temperature strength and corrosion resistance. |
| Iron (Fe) | Balance (~39.5–46%) | Offers structural integrity and thermal stability. |
| Chromium (Cr) | 19–23% | Enhances resistance to oxidation and scaling. |
| Carbon (C) | 0.05–0.10% | Improves creep strength and high-temperature performance. |
| Manganese (Mn) | ≤1.5% | Enhances toughness and ductility. |
| Silicon (Si) | ≤1.0% | Improves oxidation resistance. |
| Aluminum (Al) | ≤0.15% | Adds oxidation resistance. |
| Titanium (Ti) | ≤0.15% | Contributes to creep strength and stability. |
Key Properties of Alloy 800H
| Property | Value | Significance |
|---|---|---|
| Density | ~7.94 g/cm³ | Ensures structural stability and durability. |
| Melting Point | ~1357–1400°C | Suitable for high-temperature environments. |
| Tensile Strength | ≥450 MPa | Provides resistance to mechanical stress. |
| Yield Strength | ≥170 MPa | Ensures reliability under sustained loads. |
| Elongation | ≥30% | Offers excellent ductility and formability. |
| Oxidation Resistance | Excellent up to 1100°C | Ideal for prolonged exposure to high temperatures. |
Applications of Alloy 800H
| Application | Industry | Details |
|---|---|---|
| Heat Exchangers | Energy, Chemical | Performs well under thermal cycling and corrosive environments. |
| Furnace Components | Manufacturing | Ideal for radiant tubes, retorts, and other high-temperature parts. |
| Petrochemical Processing | Oil and Gas | Suitable for catalytic reforming and hydrocarbon processing. |
| Power Generation | Energy | Used in steam generators and superheaters. |
| Nuclear Industry | Energy | Ideal for structural components in reactor environments. |
Specifications and Standards of Alloy 800H
| Specification | Details |
|---|---|
| Form | Available in plates, sheets, bars, and tubes. |
| Purity | High-purity alloy with precise elemental control. |
| Standard Compliance | ASTM B409, ASME SB-409, UNS N08810. |
Advantages and Limitations of Alloy 800H
| Advantages | Limitations |
|---|---|
| Excellent strength and creep resistance at high temperatures. | Limited corrosion resistance in sulfur-rich environments. |
| Outstanding oxidation and scaling resistance up to 1100°C. | Not ideal for low-temperature applications. |
| Good structural stability under thermal cycling. | Higher cost compared to standard stainless steels. |
| Easily fabricated and welded using standard techniques. | Requires specific heat treatments for optimal performance. |
Frequently Asked Questions (FAQs)
What is Alloy 800H?
Alloy 800H is a high-performance nickel-iron-chromium alloy designed for high-temperature applications, offering excellent strength, oxidation resistance, and thermal stability.
What industries use Alloy 800H?
It is widely used in energy, petrochemical, power generation, and manufacturing industries for components exposed to extreme heat and stress.
What are the differences between Alloy 800 and 800H?
Alloy 800H has higher carbon content than Alloy 800, providing improved creep strength and better performance at elevated temperatures.
How does Alloy 800H perform in oxidizing environments?
It exhibits excellent oxidation resistance up to 1100°C, making it suitable for prolonged exposure to high-temperature, oxidizing conditions.
Is Alloy 800H weldable?
Yes, Alloy 800H can be welded using standard techniques, but post-weld heat treatment is recommended for optimal performance.
Conclusion
Alloy 800H is a robust and versatile material, specifically engineered for high-temperature and high-stress environments. Its combination of strength, oxidation resistance, and thermal stability makes it a preferred choice for industries such as petrochemical, energy, and manufacturing.
With its proven performance and adaptability, Alloy 800H continues to be a critical material for applications requiring reliability and durability in extreme conditions.