Alloy 702,Inconel 702,UNS N07702，EFORU

### **Alloy 702 / INCONEL® 702 (UNS N07702) - Technical Datasheet** --- #### **1. Overview** **INCONEL® 702** is a nickel-chromium-aluminum alloy designed for exceptional oxidation resistance and high-temperature strength. This precipitation-hardenable superalloy maintains excellent mechanical properties and surface stability at temperatures up to 1200°C (2200°F), making it particularly suitable for high-temperature heating elements, furnace components, and other applications requiring reliable performance in oxidizing environments. --- #### **2. Chemical Composition (Weight %)** The composition is balanced for optimal high-temperature performance and oxidation resistance. | Element | Content (%) | Role & Benefit | |---------|-------------|----------------| | **Nickel (Ni)** | Balance | Austenitic matrix providing high-temperature strength | | **Chromium (Cr)** | 14.0 - 17.0 | Primary oxidation resistance through Cr₂O₃ scale formation | | **Aluminum (Al)** | 2.75 - 3.50 | Enhances oxidation resistance and provides precipitation hardening | | **Titanium (Ti)** | 0.25 - 0.75 | Secondary precipitation hardening element | | **Iron (Fe)** | 0.50 max | Controlled impurity | | **Manganese (Mn)** | 0.50 max | Deoxidizer and workability agent | | **Silicon (Si)** | 0.50 max | Improves oxidation resistance | | **Carbon (C)** | 0.05 max | Controlled for optimal high-temperature properties | | **Copper (Cu)** | 0.50 max | Controlled impurity | | **Zirconium (Zr)** | 0.01 - 0.10 | Improves oxidation resistance and grain boundary strength | | **Boron (B)** | 0.003 - 0.010 | Enhances creep strength | *Note: "INCONEL" is a registered trademark of Special Metals Corporation* --- #### **3. Physical Properties** The physical properties support extreme high-temperature applications. | Property | Value | |----------|-------| | **Density** | 8.05 g/cm³ (0.291 lb/in³) | | **Melting Point** | 1360-1410°C (2480-2570°F) | | **Specific Heat (20°C)** | 460 J/kg·K | | **Thermal Conductivity** | 15.2 W/m·K (at 20°C) | | **Mean Coefficient of Thermal Expansion** | 14.0 × 10⁻⁶/°C (20-300°C) | | **Electrical Resistivity** | 1.18 μΩ·m | | **Modulus of Elasticity** | 214 GPa (31.0 × 10⁶ psi) | | **Magnetic Permeability** | Essentially non-magnetic | --- #### **4. Mechanical Properties** The alloy offers excellent high-temperature strength and stability. **Annealed Condition:** | Property | Value | |----------|-------| | **Tensile Strength** | 690-860 MPa (100-125 ksi) | | **Yield Strength (0.2% Offset)** | 345-515 MPa (50-75 ksi) | | **Elongation** | 30-45% | | **Hardness** | 85-100 HRB | **Aged Condition (900°C/1650°F for 16 hours):** | Property | Value | |----------|-------| | **Tensile Strength** | 860-1030 MPa (125-150 ksi) | | **Yield Strength** | 620-790 MPa (90-115 ksi) | | **Elongation** | 20-35% | | **Hardness** | 25-35 HRC | **Elevated Temperature Properties (1100°C/2000°F):** | Property | Value | |----------|-------| | **Tensile Strength** | 55 MPa (8 ksi) | | **Yield Strength** | 40 MPa (6 ksi) | | **Creep Rupture Strength (1000h)** | 15 MPa (2 ksi) | --- #### **5. Heat Treatment** **Solution Treatment:** 1150-1200°C (2100-2190°F) for 1-2 hours, rapid cool **Aging Treatment:** 850-950°C (1560-1740°F) for 8-16 hours, air cool **Stress Relieving:** 870°C (1600°F) for 1 hour per inch of thickness --- #### **6. Product Applications** **INCONEL 702** serves in extreme high-temperature oxidizing environments: - **Industrial Heating:** - High-temperature furnace elements - Radiant heating tubes - Heat treatment fixtures - Sintering furnace components - **Aerospace Industry:** - Jet engine combustion chambers - Afterburner components - Turbine seals - High-temperature fasteners - **Heat Processing Equipment:** - Muffles and retorts - Heat exchanger tubes - Thermocouple protection sheaths - Brazing fixtures - **Chemical Processing:** - High-temperature reactor components - Catalytic converter parts - Process heating elements - High-temperature instrumentation - **Power Generation:** - Gas turbine components - Heat recovery system parts - High-temperature springs - Power plant furnace parts --- #### **7. International Standards** The material conforms to various international specifications: | Standard | Specification | |----------|---------------| | **ASTM** | ASTM B637 - Precipitation-Hardening Nickel Alloy Bars, Forgings, and Forking Stock | | **UNS** | UNS N07702 | | **AMS** | AMS 5547 (Sheet, Strip, Plate) | | **Aerospace** | AMS 5719 (Bar and Forgings) | | **European** | EN 10095 - NiCr15Fe7MoTiAl | | **ISO** | ISO 9723 - NiCr15Fe7MoTiAl | --- #### **8. Oxidation Resistance** - **Exceptional** oxidation resistance up to 1200°C (2200°F) - **Excellent** resistance to cyclic oxidation - **Good** performance in sulfur-containing atmospheres - **Superior** carburization resistance - **Excellent** scale adhesion and spallation resistance - **Maintains** surface stability during thermal cycling --- #### **9. Fabrication Characteristics** - **Machining:** Can be machined using standard methods for high-temperature alloys - **Welding:** Good weldability using GTAW with matching filler metal - **Forming:** Good hot working characteristics; requires care in cold forming - **Heat Treatment:** Responds well to precipitation hardening treatments - **Surface Preparation:** Requires clean surface for optimal high-temperature performance --- #### **10. Special Properties** - **Oxidation Resistance:** Forms protective Al₂O₃ and Cr₂O₃ surface scales - **Thermal Stability:** Maintains properties during long-term high-temperature exposure - **Electrical Properties:** Suitable for electrical heating applications - **Temperature Capability:** Continuous service to 1200°C (2200°F) - **Cyclic Oxidation:** Excellent resistance to thermal cycling damage --- #### **11. Summary** **INCONEL® 702 (UNS N07702)** represents a premium nickel-chromium-aluminum superalloy engineered for extreme high-temperature applications requiring exceptional oxidation resistance and reliable mechanical properties. Its optimized composition, featuring high aluminum content for enhanced oxidation protection and precipitation hardening, delivers superior performance in the most demanding thermal environments. The alloy's ability to maintain surface stability and structural integrity at temperatures up to 1200°C, combined with good fabricability and consistent performance, makes it an ideal choice for high-temperature heating elements, furnace components, and aerospace applications. Governed by comprehensive standards including AMS 5547 and ASTM specifications, INCONEL 702 continues to be the material of choice for applications where oxidation resistance and high-temperature reliability are paramount.

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 1726 gallon liquid totes Special package is available on request.