Alloy 800HT,Incoloy 800HT ,N08811,E FORU

British Specs:BS 3072 BS 3073 BS 3074 BS 3075 BS 3076 NA15，American Specs:AMS 5766 Bar and Forgings AMS 5871 Sheet, Strip and Plate ASTM B408 ASTM B564 ASTM A240 ASTM A480，German Specs:WS 1.4876 WS 1.4958 WS 1.4959

**Technical Datasheet: Alloy 800HT / Incoloy 800HT (UNS N08811)** --- ### **1.0 Product Overview** **Alloy 800HT** (commercially known as **Incoloy 800HT**, UNS **N08811**) is an advanced nickel-iron-chromium superalloy optimized for maximum high-temperature performance. As an enhanced version of Alloy 800H, it features stricter control of carbon, aluminum, and titanium content (with Al + Ti ≥ 1.20%), delivering superior creep rupture strength, oxidation resistance, and microstructural stability at temperatures up to 815°C (1500°F). This alloy is ideal for critical components in aggressive thermal environments. --- ### **2.0 Chemical Composition (wt%)** | Element | Content (ASTM B409/ASME SB-409) | Role | |---------|----------------------------------|------| | Ni | 30.0–35.0 | Austenitic matrix stability, oxidation/carburization resistance | | Cr | 19.0–23.0 | High-temperature oxidation and sulfidation resistance | | Fe | ≥39.5 | Base element | | C | 0.06–0.10 | Enhanced carbide strengthening for creep resistance | | Al | 0.25–0.60 | Forms stable protective oxide scale | | Ti | 0.25–0.60 | Stabilization and gamma-prime precipitation strengthening | | Mn | ≤1.50 | Improves hot workability | | Si | ≤1.00 | Enhances oxidation/carburization resistance | | S | ≤0.015 | Minimized to avoid hot shortness | | Cu | ≤0.75 | — | *Note: Al + Ti ≥ 1.20% for UNS N08811, ensuring optimized high-temperature performance.* --- ### **3.0 Physical Properties** | Property | Value | Condition | |----------|-------|-----------| | Density | 8.03 g/cm³ (0.29 lb/in³) | RT | | Melting Range | 1354–1384°C (2470–2520°F) | — | | Specific Heat | 460 J/kg·K (0.11 Btu/lb·°F) | 21°C (70°F) | | Thermal Conductivity | 15.6 W/m·K (9.0 Btu·in/hr·ft²·°F) | 21°C (70°F) | | Thermal Expansion | 16.6 × 10⁻⁶ /K | 20–650°C | | Electrical Resistivity | 116 μΩ·cm (45.8 μΩ·in) | 21°C (70°F) | | Modulus of Elasticity | 201 GPa (29.1 × 10⁶ psi) | RT | | Magnetic Permeability | <1.05 | Essentially non-magnetic | --- ### **4.0 Mechanical Properties** **Room-Temperature Properties (Solution-Annealed Condition)** - **Tensile Strength:** 450 MPa min (65 ksi min) - **Yield Strength (0.2% Offset):** 170 MPa min (25 ksi min) - **Elongation:** 30% min (in 2 inches) - **Hardness:** 70–90 HRB **Elevated Temperature Performance** - **Max Continuous Service Temperature:** 815°C (1500°F) - **Creep Strength:** Superior to Alloy 800H under sustained loads - **Stress Rupture Life:** Excellent long-term performance at 650–815°C - **Oxidation Resistance:** Suitable for cyclic and continuous service up to 1150°C (2100°F) --- ### **5.0 International Standards** | Standard Type | Number | Description | |--------------|--------|-------------| | UNS | N08811 | Unified Numbering System | | ASTM | B409 | Plate, Sheet, and Strip | | ASTM | B408 | Rod and Bar | | ASTM | B407 | Seamless Pipe and Tube | | ASME | SB-409 | Boiler and Pressure Vessel Code | | EN/DIN | 1.4959 | X8NiCrAlTi32-21 (Enhanced) | | ISO | 6207 | Nickel alloy wrought products | --- ### **6.0 Product Forms** - **Plate & Sheet:** Thickness 0.5–100 mm - **Rod & Bar:** Diameter 5–300 mm - **Tubing & Pipe:** Seamless/welded, OD 3–500 mm - **Wire:** Welding and fabrication wire (ERNiCrFe-8) - **Forgings:** Custom shapes for critical applications --- ### **7.0 Applications** **Petrochemical Industry** - Steam methane reformer outlet headers - Ethylene cracking furnace tubes and pigtails - Pyrolysis reactor components - Hydroprocessing unit heaters **Power Generation** - Nuclear reactor core components - Heat exchanger tubing in advanced gas-cooled reactors - Superheater and reheater tubes - Gas turbine combustion components **Industrial Heating** - Radiant tubes in heat treatment furnaces - Retorts and muffles - Heat treatment fixtures and trays - High-temperature fans and dampers **Aerospace & Defense** - Afterburner components - Rocket engine parts - High-temperature fasteners --- ### **8.0 Fabrication Notes** - **Welding:** Use GTAW/TIG with ERNiCrFe-8 filler. Preheating not required; post-weld solution annealing recommended for critical applications. - **Hot Working:** Forge or hot work at 1150–1200°C (2100–2190°F). - **Cold Working:** Intermediate annealing at 980–1065°C (1800–1950°F) for severe deformation. - **Heat Treatment:** Solution anneal at 1120–1170°C (2050–2140°F) followed by rapid cooling to optimize creep properties. --- ### **9.0 Quality Assurance** - Certification to EN 10204 3.1/3.2 - Ultrasonic testing for plate and bar products - Grain size control (ASTM 3–6 for optimal creep resistance) - High-temperature mechanical testing available --- ### **10.0 Key Advantages over Alloy 800H** - **Enhanced High-Temperature Strength:** Higher Al + Ti content improves creep rupture life. - **Improved Microstructural Stability:** Resists sigma phase formation and embrittlement. - **Optimized Oxidation Resistance:** Superior performance in cyclic thermal environments. - **Certified for Critical Applications:** Compliant with nuclear and ASME codes. --- **Contact Us** For technical support, certification details, or custom product inquiries, contact our engineering team.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1910 gallon liquid totes Special package is available on request.