Alloy 800 Plate UNS N08800 Nickel-Iron-Chromium Superalloy ASTM B409 for High-Temperature Applications
1. Product Attributes
| Material Grade | Alloy 800 / 800H / 800HT |
|---|---|
| UNS Designation | N08800 / N08810 / N08811 |
| European Standard | 1.4876 (X10NiCrAlTi32-21) |
| Japanese Standard | NCF 800 |
| Chinese Standard | NS1101 / NS1102 / NS1103 |
| Specification | ASTM B409 / ASME SB-409 |
| Product Form | Plate / Sheet |
| Thickness Range | 3mm – 50mm+ |
| Width Range | 1000mm – 2500mm |
| Length Range | 2000mm – 6000mm |
| Surface Finish | No.1, 2B, BA, Pickled, Polished |
| Brand | DINGSCO |
2. Material Overview
Alloy 800 (UNS N08800) is a nickel-iron-chromium superalloy engineered for exceptional performance in high-temperature environments. With a nominal composition of 30-35% Nickel, 19-23% Chromium, and a minimum of 39.5% Iron, this austenitic alloy delivers outstanding resistance to oxidation, carburization, and corrosion while maintaining structural stability under prolonged thermal exposure.
The alloy remains fully austenitic across its entire service range and resists sigma-phase embrittlement, making it a reliable choice for critical high-temperature components. Its balanced chemistry provides superior creep and stress-rupture properties compared to standard stainless steels.
Key Variants:
• Alloy 800 (UNS N08800): Optimized for general high-temperature applications where creep and rupture strength are not the primary design factors.
• Alloy 800H (UNS N08810): Features a restricted carbon range (0.05-0.10%) and high-temperature annealing for superior creep and stress-rupture properties.
• Alloy 800HT (UNS N08811): Further restricted in carbon, aluminum (0.25-0.60%), and titanium (0.25-0.60%) to maximize high-temperature creep resistance.
3. Chemical Composition
| Element | Incoloy 800 UNS N08800 (wt%) | Incoloy 800H UNS N08810 (wt%) | Incoloy 800HT UNS N08811 (wt%) |
|---|---|---|---|
| Nickel (Ni) | 30.0 – 35.0 | 30.00 – 35.00 | 30.00 – 34.00 |
| Chromium (Cr) | 19.0 – 23.0 | 19.00 – 23.00 | 19.00 – 23.00 |
| Iron (Fe) | ≥ 39.5 (Balance) | Balance | Balance |
| Carbon (C) | ≤ 0.10 | ≤ 0.10 | ≤ 0.12 |
| Silicon (Si) | ≤ 1.0 | ≤ 1.00 | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.5 | ≤ 1.50 | ≤ 2.00 |
| Aluminum (Al) | 0.15 – 0.60 | 0.15 – 0.60 | 0.15 – 0.60 |
| Titanium (Ti) | 0.15 – 0.60 | 0.15 – 0.60 | 0.15 – 0.60 |
| Copper (Cu) | ≤ 0.75 | ≤ 0.75 | — |
| Phosphorus (P) | — | ≤ 0.030 | ≤ 0.030 |
| Sulfur (S) | ≤ 0.015 | ≤ 0.015 | ≤ 0.015 |
4. Physical Properties
| Property | Value | Unit |
|---|---|---|
| Density | 8.0 | g/cm³ |
| Melting Point | 1357 – 1385 | °C |
| Specific Heat (at 20°C) | 460 | J/kg·K |
| Electrical Resistivity (at 20°C) | 99 | μΩ·cm |
| Thermal Conductivity (at 20°C) | 12.6 | W/m·K |
| Thermal Conductivity (at 100°C) | 14.1 | W/m·K |
| Thermal Conductivity (at 200°C) | 16.1 | W/m·K |
| Thermal Conductivity (at 500°C) | 20.6 | W/m·K |
| Thermal Conductivity (at 800°C) | 25.1 | W/m·K |
| Curie Point | -115 | °C |
| Magnetic Property | Non-Magnetic | — |
5. Mechanical Properties
| Property | ASTM B409 (Room Temp.) | JIS G4902 |
|---|---|---|
| Yield Strength (YS, 0.2% Offset) | ≥ 205 MPa (N/mm²) | ≥ 205 N/mm² |
| Tensile Strength (TS) | ≥ 520 MPa (N/mm²) | ≥ 520 N/mm² |
| Elongation (EL) | ≥ 30% | ≥ 30% |
| Hardness (HV) | — | ≤ 182 |
| Hardness (HB) | — | ≤ 179 |
High-Temperature Tensile Strength
| Temperature (°C) | Tensile Strength (MPa, Typical) |
|---|---|
| Room Temperature | 552 |
| 200 | 485 |
| 400 | 445 |
| 600 | 390 |
| 700 | 245 |
| 800 | 155 |
6. Corrosion & Oxidation Resistance Comparison
| Property | Alloy 800 (UNS N08800) | SUS 310S | NAS 600 (Inconel 600) |
|---|---|---|---|
| Oxidation Resistance (up to 1000°C) | Excellent — forms protective Cr₂O₃ scale | Good — susceptible above 1050°C | Excellent — comparable to Alloy 800 |
| Carburization Resistance | Excellent — high Ni content inhibits carbon diffusion | Moderate | Good |
| Nitric Acid Corrosion | Good | Good | Good |
| Stress Corrosion Cracking (SCC) | Superior — outperforms standard austenitic SS | Moderate — susceptible in chloride environments | Excellent |
| Molten Salt Corrosion | Good | Moderate | Good |
| Sigma-Phase Embrittlement | Resistant — does not precipitate σ phase during service | Susceptible | Resistant |
| Intergranular Attack | Resistant with proper heat treatment | Susceptible after sensitization | Resistant |
7. Material Characteristics
High-Temperature Strength
Maintains excellent mechanical integrity at elevated temperatures up to 816°C (1500°F). The austenitic structure remains stable without sigma-phase embrittlement even after prolonged exposure, ensuring long-term reliability in critical applications.
Oxidation Resistance
High nickel and chromium content promotes the formation of a protective chromium oxide (Cr₂O₃) scale at elevated temperatures. Oxidation resistance surpasses SUS 310S and approaches that of Inconel 600, particularly above 600°C.
Carburization Resistance
The high nickel content effectively inhibits carbon diffusion into the alloy matrix, preventing carburization-related embrittlement in hydrocarbon processing environments such as ethylene cracking and petrochemical reforming.
Corrosion Resistance
Exhibits good resistance to oxidizing corrosive media including nitric acid and nitric-sulfuric acid mixtures. Stress corrosion cracking resistance is significantly superior to standard austenitic stainless steels.
Weldability
Welds similarly to standard austenitic stainless steel. Compatible with TIG, MIG, and manual arc welding processes. Proper filler metal selection and post-weld heat treatment ensure optimal joint integrity.
Fabrication
Hot working temperature: 1000–1230°C. Simple forming can be performed below 850°C. Avoid the 650–850°C range to prevent cracking. Cold workability matches austenitic stainless steel with slightly lower work hardening characteristics.
Heat Treatment
• Annealing: 980–1100°C followed by rapid cooling
• Stress-Relieving: 780–870°C followed by air cooling
8. Product Image Display
9. Supply Forms
| Form | Specification | Available Grades |
|---|---|---|
| Plates | Thickness: 3mm – 50mm+ | Width: 1000mm – 2500mm | Length: 2000mm – 6000mm | Alloy 800 / 800H / 800HT |
| Sheets | Thickness: 0.5mm – 3mm | Width: 1000mm / 1219mm / 1500mm | Length: 2000mm / 2438mm / 3000mm | Alloy 800 / 800H / 800HT |
| Strips / Coils | Custom thickness and width per request | Alloy 800 / 800H |
| Custom Cut Parts | Water jet, laser, plasma cutting available | Alloy 800 / 800H / 800HT |
Surface Finishes Available: Hot Rolled (No.1), Cold Rolled (2B), Bright Annealed (BA), Pickled, Polished (180#, 320#, 400#, 600#)
10. Typical Applications
Heat Exchangers & Steam Generators
Tubing and plates for power plant superheaters, steam generator tubing, and high-temperature heat exchangers requiring long-term thermal stability.
Petrochemical & Refinery
Ethylene cracking furnace components, reformer tubes, process piping, and pressure vessels exposed to hydrocarbon streams at elevated temperatures.
Industrial Furnaces
Heat-treating baskets, trays, fixtures, muffles, and radiant tubes operating in carburizing or oxidizing atmospheres.
Nitric Acid Equipment
Condensers, heating coils, and storage vessels for nitric acid and nitric-sulfuric acid mixtures.
Thermocouple Protection Tubes
Sheathed heater outer tubes and thermocouple protection tubes for high-temperature measurement applications.
Heat Treatment Furnace Parts
Components requiring prolonged exposure to temperatures up to 1000°C with resistance to thermal cycling and oxidation.
11. DINGSCO — Professional Nickel Alloy Manufacturer
DINGSCO is a premier manufacturer and supplier of high-performance nickel alloy products, serving global industries with comprehensive material solutions.
Quality Assurance
Our mission is to provide our customers only with the best quality products. As an ISO 9001:2015, PED 2014/68/EC, and API 6A certified manufacturer, we enforce strict quality control at every production stage — from raw material sourcing to final inspection and certification.
Science & Technology Innovation Strategy
We pay close attention to customer needs, implement product innovation, and leverage our comprehensive range of product types and material grades to provide customers with one-stop service. Continuous improvement drives our material research, process optimization, and equipment upgrades.
Cooperation
We are pleased to help others and glad to accept the hand of others. We actively participate in team collaboration and support decision-making. We share our experience with each other and excel at cooperating with different types of colleagues across the global supply chain.
12. Material Selection
| Alloy | UNS | Key Feature | Max Service Temp. |
|---|---|---|---|
| Alloy 800 | N08800 | General high-temp, oxidation & carburization resistant | ~816°C (1500°F) |
| Alloy 800H | N08810 | Superior creep & stress-rupture properties | ~870°C (1600°F) |
| Alloy 800HT | N08811 | Maximum creep resistance for critical applications | ~870°C (1600°F) |
| Inconel 600 | N06600 | Excellent oxidation resistance, higher Ni content | ~1093°C (2000°F) |
| Inconel 601 | N06601 | Superior oxidation resistance with Al addition | ~1200°C (2190°F) |
| Incoloy 825 | N08825 | Enhanced corrosion resistance in reducing environments | ~540°C (1000°F) |
| SUS 310S | S31008 | Economical alternative for moderate temperatures | ~1050°C (1920°F) |
13. Customized Products
DINGSCO offers comprehensive customization services to meet your exact project specifications:
Custom Dimensions
Plates and sheets cut to your specified length, width, and thickness. Non-standard sizes available upon request with short lead times.
Custom Surface Finish
Choose from hot rolled, cold rolled, pickled, bright annealed, or polished finishes (up to mirror finish) to match your application requirements.
Custom Certification
Full material test certificates (MTC) to EN 10204 3.1 / 3.2. Additional NDT testing (UT, PT, RT) available per project requirements.
Value-Added Processing
Water jet cutting, laser cutting, plasma cutting, bevelling, drilling, and edge preparation services to reduce your downstream processing costs.
Payment & Shipping Terms
| Minimum Order Quantity | Negotiable |
|---|---|
| Price | Negotiable |
| Packaging Details | According to Customers' Requests |
| Delivery Time | 7 days (Sample Order) |
| Payment Terms | T/T |
| Supply Ability | Negotiable |
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.