What Is a Seamless Incoloy 800H Pipe?
A Seamless Incoloy 800H Pipe is a premium nickel-iron-chromium superalloy piping solution engineered for sustained performance in high-temperature industrial environments. Unlike welded alternatives, our seamless pipes are hot-pierced and cold-finished from a single solid billet, ensuring a uniform grain structure and superior burst pressure resistance.
The”800H”(UNS N08810) variant is specifically designed to bridge the gap between standard alloys and ultra-high-temp superalloys. By precisely controlling the carbon content （0.05% to 0.10%） and applying a specialized solution annealing treatment, Incoloy 800H achieves significantly enhanced creep and stress-rupture strength at service temperatures exceeding 1100 °F (593 °C).
Size Range: OD 6–457 mm · WT 0.5–45 mm
Key Features and Advantages
- Enhanced Creep-Rupture Properties: The controlled chemistry and high-temperature anneal stabilize the grain size (typically ASTM No. 5 or coarser), providing maximum resistance to long-term deformation.
- Oxidation & Carburization Resistance: The high chromium (19% to 23%) and nickel (30% to 35%) content creates a robust protective layer against aggressive flue gases and carburizing atmospheres.
- Structural Integrity under Thermal Cycling: The seamless construction eliminates the Heat Affected Zone (HAZ) vulnerabilities, making it ideal for systems with frequent temperature fluctuations.
- Corrosion Versatility: Beyond heat resistance, it maintains excellent stability in various aqueous environments, resisting stress-corrosion cracking (SCC) better than standard stainless steels.
- Excellent Fabricability: Despite its high strength, 800H maintains good ductility and can be easily welded using standard industrial techniques (GTAW/GMAW).
Technical Specifications & Standards
At WENZHOU Xinzhe TECH CO., LTD., our Incoloy 800H pipes are manufactured to meet and exceed global engineering requirements:
- ASTM B407 / ASME SB407: Standard Specification for Nickel-Iron-Chromium Alloy Seamless Pipe and Tube.
- ASTM B829: General requirements for nickel and nickel alloy seamless pipes.
- UNS N08810: Ensuring precise chemical balance for high-temp stability.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Incoloy 800H.
Equivalent Grade
| UNS | Common grade name | EN material number | EN steel name | JIS grade | GB/T grade |
|---|---|---|---|---|---|
| N08810 | Incoloy 800H | 1.4958 | X5NiCrAlTi31-20 | NCF800H | NS1102 / NS112 (legacy) |
Grade correspondence does not make ASTM, ASME, EN, JIS and GB delivery requirements interchangeable. Confirm chemistry, heat treatment, mechanical properties, dimensions, testing and certification against the purchase specification. See the grade designation index.
Chemical Composition
The composition of Incoloy 800H is carefully balanced to achieve its superior high-temperature strength and oxidation resistance.
| Grade | Ni | Cu | Fe | Mn | C | Si | S | Cr | Al | Ti | P | Other |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 800 | 30.00-35.00 | ≤0.75 | ≥39.50 | ≤1.50 | ≤0.10 | ≤1.00 | ≤0.015 | 19.00-23.00 | 0.15-0.60 | 0.15-0.60 | ≤0.045 | – |
| 800H | 30.00-35.00 | ≤0.75 | ≥39.5 | ≤1.50 | 0.05-0.10 | ≤1.00 | ≤0.015 | 19.00-23.00 | 0.15-0.60 | 0.15-0.60 | ≤0.045 | – |
| 800HT | 30.00-35.00 | ≤0.75 | ≥39.5 | ≤1.50 | 0.06-0.10 | ≤1.00 | ≤0.015 | 19.00-23.00 | 0.25-0.60 | 0.25-0.60 | ≤0.045 | AL+Ti=0.85-1.20 |
Typical Mechanical Properties
Incoloy 800H is specifically designed to maintain its strength and shape in high-stress, high-temperature environments.
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| ≥ 450 MPa | ≥ 170 MPa | ≥ 30% | Not an acceptance limit in ASTM B407 |
Typical Physical Properties
These physical properties highlight the material’s ability to perform reliably under a wide range of conditions.
| Density | Melting Point | Thermal Expansion | Thermal Conductivity | Modulus of Elasticity | Electrical Resistivity |
|---|---|---|---|---|---|
| 7.94 g/cm³ | 1357 – 1385 °C approx. | 14.4 µm/m·°C (20-100°C) | 11.5 W/m·K (20°C) | 199 GPa | 0.989 µΩ·m (20°C) |
Size Tolerance Chart (mm)
Cold-Finished Pipes and Tubes:
| Specified/Calculated Nominal OD (Inches) | Permissible Variation (Inches) | Specified/Calculated Nominal OD (mm) | Permissible Variation (mm) |
| 0.500 to 5⁄8, excl. | ±0.005 | 12.7 to 15.8, excl. | ±0.127 |
| 5⁄8 to 1 1⁄2, incl. | ±0.0075 | 15.8 to 38.1, incl. | ±0.190 |
| Over 1 1⁄2 to 3 1⁄2, incl. | ±0.010 | Over 38.1 to 88.9, incl. | ±0.254 |
| Over 3 1⁄2 to 4 1⁄2, incl. | ±0.015 | Over 88.9 to 114.3, incl. | ±0.381 |
| Over 4 1⁄2 to 6, incl. | ±0.020 | Over 114.3 to 152.4, incl. | ±0.508 |
| Over 6 to 6 5⁄8, incl. | ±0.025 | Over 152.4 to 168.3, incl. | ±0.635 |
| Specified/Calculated Nominal OD (Inches) | Permissible Variation (Inches) | Specified/Calculated Nominal OD (mm) | Permissible Variation (mm) |
| 2 1⁄2 to 5 1⁄2, excl. | ±0.031 | 63.5 to 139.7, excl. | ±0.787 |
| 5 1⁄2 to 9 1⁄4, incl. | ±0.047 | 139.7 to 234.9, incl. | ±1.19 |
| Condition | Specified/Calculated Nominal OD (Inches) | Permissible Variation (Wall Thickness) |
| Cold-Finished | 0.500 to 5⁄8, excl. | ±15.0% |
| 5⁄8 to 4 1⁄2, incl. | ±10.0% | |
| Over 4 1⁄2 to 6 5⁄8, incl. | ±12.5% | |
| Hot-Finished | 2 1⁄2 to 9 1⁄4, incl. | ±12.5% |
Industrial Applications of Seamless Incoloy 800H Pipe
The unique combination of high-temperature creep strength and exceptional oxidation resistance makes Seamless Incoloy 800H (UNS N08810) the preferred alloy for critical thermal processing environments:
Heat Treating & Industrial Furnaces
Essential for radiant tubes, furnace muffles, retorts, and high-temperature fixtures where structural stability is required up to 1500°F(815°C).
Power Generation & Utilities
Widely utilized in superheater and reheater tubing for fossil-fired and nuclear power plants, as well as steam generator components.
Petrochemical & Refining
Ideal for ethylene pyrolysis furnace tubes (pigtails and headers), steam/hydrocarbon reforming, and high-temperature burner components.
Waste-to-Energy
High-durability components for waste incinerators, combustion chambers, and exhaust systems handling aggressive flue gases.
Frequently Asked Questions
What sizes are available for Incoloy 800H seamless pipe?
Continuous supply covers OD 6–457 mm and WT 0.5–45 mm. Requirements outside this range are reviewed against mill capability on request.
Which specification governs Incoloy 800H seamless pipe?
ASTM B407 / ASME SB407 is the governing seamless specification for Incoloy 800H pipe (Grade H, carbon 0.05–0.10% for creep rupture strength); the edition in force at order time is stated on the quotation and purchase order.
What inspection documents are provided?
Each order is documented with a mill test certificate stating heat chemistry and mechanical test results. EN 10204 3.1 certification, hydrostatic testing, eddy-current or ultrasonic inspection and PMI are performed when specified in the purchase order.
Technical review: page data reviewed by the Xinzhe technical desk on 2026-09-27. Property values are typical reference data compiled from Special Metals Corporation alloy data sheets and the governing ASTM specifications; they are not acceptance guarantees unless stated in the purchase order. “Incoloy” is a trademark of Special Metals Corporation, used here to identify the alloy family only.
Ready to Request a Quotation?
Send the NPS and schedule (or actual OD and wall), quantity, length, end finish and the inspection items you need as acceptance criteria — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.
