Alloy 800H,Incoloy 800H ,N08810,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

### **Introduction to Alloy 800H / Incoloy 800H / UNS N08810** **Alloy 800H** (commonly known by its trade name **Incoloy 800H** and UNS designation **N08810**) is a widely used nickel-iron-chromium superalloy known for its exceptional strength and resistance to high-temperature corrosion and oxidation. It is a controlled-composition version of Alloy 800, with specified levels of carbon, aluminum, and titanium to optimize its elevated temperature performance. The "H" denotes its high-temperature characteristics, achieved through a controlled carbon content and an appropriate annealing treatment to produce a coarse grain structure. This structure provides superior creep and stress-rupture properties compared to the standard Alloy 800, making it a premier choice for demanding high-temperature applications. --- ### **Chemical Composition** The chemical composition of Alloy 800H (N08810) is strictly controlled to ensure consistent high-temperature performance. The typical composition ranges are as follows: | Element | Content (%) (ASTM B409) | Role in the Alloy | | :--- | :--- | :--- | | **Nickel (Ni)** | 30.0 - 35.0 | Provides austenitic structure, resistance to oxidation and carburization. | | **Chromium (Cr)** | 19.0 - 23.0 | Confers resistance to oxidation, sulfidation, and other high-temperature corrosives. | | **Iron (Fe)** | ≥ 39.5 | Balance; forms the base of the alloy matrix. | | **Carbon (C)** | 0.05 - 0.10 | **Key for "H" grade.** Strengthens the alloy at high temperatures via solid solution and carbide formation, enhancing creep resistance. | | **Aluminum (Al)** | 0.15 - 0.60 | Combines with Titanium to form γ' phase and improves oxidation resistance by forming a protective scale. | | **Titanium (Ti)** | 0.15 - 0.60 | Combines with Aluminum to form γ' phase, contributing to strengthening. | | **Manganese (Mn)** | ≤ 1.50 | Aids in hot workability and combats sulfur embrittlement. | | **Copper (Cu)** | ≤ 0.75 | - | | **Silicon (Si)** | ≤ 1.00 | Improves resistance to oxidation and carburization. | | **Sulfur (S)** | ≤ 0.015 | Impurity, kept low to prevent hot shortness. | *Note: The ratio of (Al + Ti) must be ≥ 0.85% for N08810.* --- ### **Physical Properties** | Property | Value / Condition | | :--- | :--- | | **Density** | 0.29 lb/in³ (8.03 g/cm³) | | **Melting Range** | 2470-2520°F (1354-1384°C) | | **Specific Heat** | 0.11 Btu/lb·°F (460 J/kg·K) at 70°F (21°C) | | **Thermal Expansion** | 9.2 x 10⁻⁶ /°F (16.6 x 10⁻⁶ /K) | 70-1200°F (20-650°C) | | **Thermal Conductivity** | 9.0 Btu/hr·ft·°F (15.6 W/m·K) at 70°F (21°C) | | **Electrical Resistivity** | 45.8 μΩ·in (116 μΩ·cm) at 70°F (21°C) | | **Modulus of Elasticity** | 29.1 x 10⁶ psi (201 GPa) at 70°F (21°C) | | **Magnetic Permeability** | Typically < 1.05 (Essentially non-magnetic) | --- ### **Mechanical Properties (Typical at Room Temperature)** The properties can vary with product form and heat treatment. The following are typical minimums for annealed condition. **Plate, Sheet, & Strip (ASTM B409, B408)** * **Tensile Strength:** 65 ksi (450 MPa) min * **Yield Strength (0.2% Offset):** 25 ksi (170 MPa) min * **Elongation:** 30% min *Its key advantage is the retention of strength at elevated temperatures, with excellent creep and stress-rupture properties up to 1500°F (815°C).* --- ### **International Standards** Alloy 800H / N08810 is covered by numerous international standards for different product forms. | Standard Type | Standard Number | Description | | :--- | :--- | :--- | | **UNS** | **N08810** | Unified Numbering System designation. | | **ASTM** | **B409 / B409M** | Standard Specification for Nickel-Iron-Chromium Alloy Plate, Sheet, and Strip. | | **ASTM** | **B163 / B163M** | Standard Specification for Seamless Nickel and Nickel Alloy Condenser and Heat-Exchanger Tubes. | | **ASTM** | **B165 / B165M** | Standard Specification for Nickel-Copper Alloy Seamless Pipe and Tube (often referenced for U-bend tubes). | | **ASTM** | **B167** | Standard Specification for Nickel-Chromium-Iron Alloy Seamless Pipe and Tube. | | **ASME** | **SB-409** | Equivalent to ASTM B409, approved for use in ASME Boiler and Pressure Vessel Code, Section I & VIII. | | **ASME** | **SB-163, SB-167** | ASME equivalents for tubing and pipe. | | **EN / DIN** | **1.4958 / 1.4876** | European material numbers (X5NiCrAlTi31-20 / X8NiCrAlTi32-21). Note: 1.4876 is often the direct equivalent. | | **ISO** | **6207** | Plate, sheet, and strip. | --- ### **Product Applications** Alloy 800H's unique combination of properties makes it ideal for a wide range of demanding applications, particularly in: 1. **Petrochemical & Chemical Processing:** * Steam methane reformer (SMR) components: catalyst tubes, pigtails, outlet manifolds, and header assemblies. * Ethylene cracking furnace tubes, radiant coils, and transfer line exchangers. * Equipment exposed to carburizing and oxidizing atmospheres. 2. **Power Generation:** * Heat exchangers, superheater and reheater tubing in fossil fuel and nuclear power plants. * Components for advanced gas-cooled reactors (AGRs). * Ducting and structural supports in high-temperature sections. 3. **Industrial Furnaces:** * Muffles, retorts, radiant tubes, and furnace rollers. * Baskets and fixtures for heat treating. 4. **Thermal Processing:** * Heat treatment trays and fixtures. * Components for carbonitriding and nitrocarburizing furnaces. ### **Key Characteristics Summary** * **Excellent High-Temperature Strength:** Superior creep and stress-rupture properties up to 1500°F (815°C). * **Resistance to Oxidation:** Forms a protective, adherent chromium oxide scale. * **Resistance to Carburization:** Resists carbon absorption, which can cause embrittlement. * **Good Resistance to Sulfidation:** Performs well in sulfur-containing environments. * **Stability:** Resists the formation of embrittling sigma phase after long-term exposure. * **Essentially Non-Magnetic.** In conclusion, **Alloy 800H / Incoloy 800H / UNS N08810** is a versatile, high-performance engineering material specifically designed for long-term service in high-temperature, corrosive environments, making it a cornerstone alloy in the energy, chemical, and processing industries.

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 1897 gallon liquid totes Special package is available on request.