HP Alloys Alloy 718，1

### **Product Introduction: HP Alloys Alloy 718 - Precipitation-Hardenable Nickel-Based Superalloy** **Overview** HP Alloys Alloy 718 is a high-strength, corrosion-resistant nickel-chromium alloy hardened by additions of niobium, molybdenum, titanium, and aluminum. This precipitation-hardenable superalloy is renowned for its exceptional combination of high tensile, fatigue, creep, and rupture strength at temperatures up to 700°C (1300°F). Its outstanding weldability and resistance to post-weld cracking make it particularly valuable for complex fabricated components in aerospace, oil and gas, and power generation applications. --- #### **Chemical Composition (Typical % by Weight)** | Element | Content (%) | Role & Benefit | |---------|-------------|---------------| | **Nickel (Ni)** | 50.0 - 55.0 | Primary matrix element providing corrosion resistance and stability | | **Chromium (Cr)** | 17.0 - 21.0 | Confers oxidation and corrosion resistance | | **Iron (Fe)** | Balance | Cost-effective matrix element | | **Niobium (Nb)** | 4.75 - 5.50 | Primary precipitation hardener via γ" phase (Ni3Nb) formation | | **Molybdenum (Mo)** | 2.80 - 3.30 | Solid solution strengthener and enhances creep strength | | **Titanium (Ti)** | 0.65 - 1.15 | Contributes to γ' phase (Ni3Ti) precipitation hardening | | **Aluminum (Al)** | 0.20 - 0.80 | Forms γ' phase (Ni3Al) for precipitation strengthening | | **Cobalt (Co)** | 1.00 max | Controlled residual element | | **Carbon (C)** | 0.08 max | Forms strengthening carbides | | **Manganese (Mn)** | 0.35 max | Aids in manufacturability | | **Silicon (Si)** | 0.35 max | Process control element | | **Boron (B)** | 0.006 max | Enhances creep strength and ductility | *Note: This alloy corresponds to UNS N07718/W.Nr. 2.4668* --- #### **Physical & Mechanical Properties** **Physical Properties:** - Density: 8.19 g/cm³ (0.296 lb/in³) - Melting Range: 1260-1336°C (2300-2440°F) - Thermal Expansion: 13.0 μm/m·°C @ 20-100°C - Thermal Conductivity: 11.4 W/m·K @ 100°C - Specific Heat Capacity: 435 J/kg·K @ 20°C - Modulus of Elasticity: 200 GPa (29.0 x 10⁶ psi) - Magnetic Permeability: Slightly magnetic in aged condition **Mechanical Properties (Aged Condition - Room Temperature):** - Tensile Strength: 1275 MPa (185 ksi) minimum - Yield Strength (0.2% Offset): 1035 MPa (150 ksi) minimum - Elongation: 12% minimum - Reduction of Area: 15% minimum - Hardness: HRC 36-44 **Elevated Temperature Properties:** - Excellent strength retention up to 650°C (1200°F) - Good creep resistance at temperatures up to 700°C (1300°F) - Maintains oxidation resistance up to 980°C (1800°F) for short periods --- #### **International Standards and Specifications** - **AMS 5662:** Nickel Alloy, Corrosion and Heat-Resistant, Bars, Forgings, and Rings - **AMS 5663:** Nickel Alloy, Corrosion and Heat-Resistant, Bars, Forgings, and Rings 125 ksi (862 MPa) Yield Strength - **ASTM B637:** Precipitation-Hardening Nickel Alloy Bars, Forgings, and Forging Stock - **ASME SB-637:** Pressure vessel applications - **AMS 5596:** Sheet, Strip, and Plate - **NACE MR0175/ISO 15156:** Sour service compliance - **GE S-400:** General Electric specification - **Pratt & Whitney CS-3000:** Proprietary specification --- #### **Product Applications** **Aerospace Industry:** - Gas turbine engine components (disks, blades, shafts) - Compressor and turbine sections - Afterburner components - Rocket engine parts - Aircraft structural components **Oil and Gas Industry:** - Downhole tool components - Wellhead equipment - Valve components for sour service - High-strength fasteners and bolts - Subsea equipment **Power Generation:** - Gas turbine components - Steam turbine parts - Nuclear reactor components - High-temperature fasteners - Turbine wheel seals and rings **Other Applications:** - High-temperature springs - Forming tools and dies - Chemical processing equipment - Medical implants and instruments --- #### **Key Advantages** 1. **Exceptional High-Temperature Strength**: Maintains mechanical properties at temperatures up to 700°C (1300°F) 2. **Outstanding Weldability**: Unique resistance to strain-age cracking in welded conditions 3. **Excellent Corrosion Resistance**: Good performance in various corrosive environments 4. **Superior Fatigue Resistance**: Excellent resistance to cyclic loading conditions 5. **Good Creep Rupture Strength**: Reliable long-term performance under sustained loading 6. **Versatile Heat Treatment**: Can be optimized for specific application requirements 7. **Proven Reliability**: Extensive service history in critical applications 8. **High Strength-to-Weight Ratio**: Excellent mechanical properties with moderate density --- **Conclusion** HP Alloys Alloy 718 represents a premier precipitation-hardenable nickel-based superalloy that delivers an outstanding balance of high strength, corrosion resistance, and fabricability. Its unique niobium-hardening mechanism provides exceptional mechanical properties while maintaining excellent weldability—a combination rarely found in high-strength superalloys. The alloy's proven performance across aerospace, oil and gas, and power generation applications establishes it as a material of choice for critical components where reliability, strength, and durability are paramount. Supported by comprehensive international standards and rigorous quality control, Alloy 718 continues to be the benchmark for high-performance applications demanding superior mechanical properties and long-term reliability in challenging operating environments.

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 3433 gallon liquid totes Special package is available on request.