Alloy 263,Haynes 263 Fittings,UNS N07263,E FORU

British Specs:BS HR10 BS HR206 BS HR404，American Specs:AMS 5872 Sheet Strip and Plate AMS 5886 Bar and Forgings，German Specs:WS 2.4650

### **Product Data Sheet: Alloy 263 / Haynes 263 Fittings (UNS N07263)** **Overview** **Alloy 263** (commercially known as **Haynes 263** and standardized as **UNS N07263**) is a precipitation-hardenable nickel-cobalt-chromium superalloy. It is specifically engineered to deliver an exceptional balance of **high-temperature strength, outstanding oxidation resistance, and good fabricability**. In the form of **fittings** (such as pipe, tube, socket weld, and butt-weld fittings), Alloy 263 is used to construct critical high-temperature fluid and gas conveyance systems. These components are valued for their ability to maintain structural integrity and corrosion resistance under extreme thermal and mechanical stress, making them essential in aerospace and energy applications. --- #### **1. Chemical Composition** The composition is precisely controlled to optimize high-temperature strength and environmental resistance. | Element | Content (%) (Typical) | Role in the Alloy | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance | Forms the austenitic matrix, providing base corrosion resistance and toughness. | | **Chromium (Cr)** | 19.0 - 21.0 | Imparts superior resistance to oxidation and hot corrosion. | | **Cobalt (Co)** | 19.0 - 21.0 | Solid solution strengthener; significantly enhances high-temperature strength. | | **Molybdenum (Mo)** | 5.6 - 6.1 | Provides solid solution strengthening and resistance to creep deformation. | | **Titanium (Ti)** | 1.9 - 2.4 | Primary precipitation hardener (forms γ' phase, Ni₃(Ti,Al)). | | **Aluminum (Al)** | 0.3 - 0.6 | Secondary precipitation hardener; contributes to the γ' phase. | | **Carbon (C)** | 0.04 - 0.08 | Forms carbides for grain boundary strength and stability. | | **Manganese (Mn)** | 0.60 max | Aids in manufacturability and controls sulfur. | | **Silicon (Si)** | 0.40 max | Enhances oxidation resistance. | | **Iron (Fe)** | 0.70 max | Residual element, kept low to maintain alloy integrity. | | **Boron (B)** | 0.005 max | Strengthens grain boundaries to improve creep life. | | **Zirconium (Zr)** | 0.06 max | Trace addition to enhance creep rupture properties. | --- #### **2. Physical Properties (Typical)** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.36 g/cm³ (0.302 lb/in³) | | **Melting Range** | 1330 - 1360 °C (2425 - 2480 °F) | | **Specific Heat** | 420 J/kg·K (0.10 Btu/lb·°F) @ 20°C | | **Thermal Conductivity**| 11.6 W/m·K (80.4 Btu·in/hr·ft²·°F) @ 20°C | | **Mean Coefficient of Thermal Expansion** | 12.6 x 10⁻⁶/°C (20 - 100°C) | | | 16.8 x 10⁻⁶/°C (20 - 800°C) | | **Electrical Resistivity** | 1.25 μΩ·m @ 20°C | | **Modulus of Elasticity** | 211 GPa (30.6 x 10⁶ psi) @ 20°C | --- #### **3. Key Characteristics & Mechanical Properties for Fittings** Alloy 263 fittings are typically supplied in a solution-annealed condition for optimal weldability and formability, and they develop their full strength during post-weld heat treatment (PWHT) or in-service exposure. * **High-Temperature Strength:** Excellent creep rupture strength and tensile strength at temperatures up to 800°C (1470°F). * **Excellent Oxidation Resistance:** The high Chromium content provides a protective oxide scale, allowing prolonged use in high-temperature environments. * **Good Weldability:** Fittings can be welded using GTAW (TIG) and GMAW (MIG) processes, with properties restored via a full solution anneal and age after welding. * **Thermal Stability:** Retains its microstructure and mechanical properties over long periods of exposure at high temperatures. **Typical Mechanical Properties (Precipitation-Hardened)** * **Tensile Strength:** 950 - 1200 MPa (138 - 174 ksi) * **Yield Strength (0.2% Offset):** 550 - 800 MPa (80 - 116 ksi) * **Elongation:** 20 - 30% --- #### **4. Product Applications for Fittings** Alloy 263 fittings are used in high-performance systems where reliability at elevated temperatures is paramount. * **Aerospace & Gas Turbine Engines:** * **Fuel & Hydraulic System Manifolds** * **High-Pressure Air Ducting Fittings** * **Exhaust Gas Recirculation (EGR) Systems** * **Lube Oil and Scavenge System Piping** * **Power Generation:** * **Tubing and Piping Systems** in land-based gas turbines. * **Heat Recovery Steam Generator (HRSG) Bypass Systems** * **Chemical Processing:** * **High-Temperature Reactor Piping** and associated fittings. * **Test Benches & Rigs:** * **High-Temperature, High-Pressure Fluid Conveyance Systems.** --- #### **5. International Standards** Alloy 263 fittings conform to a range of international dimensional and material specifications. | Standard Type | Standard Number | Title / Specification (Examples) | | :--- | :--- | :--- | | **Unified Numbering System (UNS)** | **N07263** | All product forms | | **ASTM International (Material)** | **ASTM B366** | Standard Specification for Factory-Made Wrought Nickel and Nickel Alloy Fittings | | **ASTM International (Pipe/Tube)** | ASTM B829 | Standard Specification for Seamless Nickel Alloy Pipe and Tube | | **Aerospace (SAE/AMS)** | **AMS 5872** | Bars, Forgings, and Rings (Common starting stock for machined fittings) | | **European (EN)** | **EN 10253** | Butt-welding pipe fittings | | | **2.4650** | Material Number (Werkstoff Nr.) | | **Dimensional Standards** | **ASME B16.9 / B16.11** | Factory-Made Wrought Buttwelding / Socket-Weld Fittings | | **Dimensional Standards** | **MIL-F-1183** | Fittings, Pipe, Hydraulic, High-Temperature, Steel and Corrosion-Resistant Steel | --- **Summary** **Alloy 263 Fittings (Haynes 263, UNS N07263)** are critical components for constructing high-integrity piping systems that operate under severe thermal and mechanical stress. Their superior high-temperature strength, excellent oxidation resistance, and proven weldability make them a reliable and long-lasting choice for the most demanding applications in aerospace propulsion, power generation, and advanced industrial systems. Compliance with international material and dimensional standards ensures quality, interchangeability, and system safety.

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 2126 gallon liquid totes Special package is available on request.