Alloy 718，Inconel 718 ，UNS N07718，EFORU

British Specs:，American Specs: AMS 5662 Bar and Forgings AMS 5663 Bar and Forgings AMS 5664 Bar and Forgings AMS 5589 Seamless Tube AMS 5590 (Tube *) AMS 5596 Sheet, Strip and Plate AMS 5597 Sheet, Strip and Plate AMS 5832 Welding Wire AMS 5914 Sheet, Strip and Foil AMS 5950 (718SPF) Sheet & Strip ASTM F3055 Powder，German Specs:

### **Product Introduction: Alloy 718 / Inconel 718 (UNS N07718)** #### **Overview** **Alloy 718** (commercially known as **Inconel® 718**) is a premier precipitation-hardenable nickel-chromium superalloy containing significant amounts of iron, niobium, and molybdenum. It is one of the most widely used superalloys due to its exceptional combination of properties: high strength, excellent fatigue resistance, and outstanding creep rupture strength up to 700°C (1300°F). The alloy exhibits superb corrosion and oxidation resistance, along with good weldability, making it the material of choice for the most demanding applications in aerospace, oil and gas, and power generation industries. A key characteristic of Alloy 718 is its unique age-hardening mechanism through the precipitation of gamma double prime (γ'') phase [Ni₃Nb], which provides exceptional strength while maintaining good microstructural stability. The alloy retains its properties for extended periods at high temperatures, demonstrating less susceptibility to strain-age cracking compared to other precipitation-hardened nickel-based superalloys. --- #### **Chemical Composition** The chemical composition of Alloy 718 (UNS N07718) is carefully balanced to achieve optimal performance: | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 50.0 - 55.0 | | **Chromium (Cr)** | 17.0 - 21.0 | | **Iron (Fe)** | Balance | | **Niobium (Nb)** | 4.75 - 5.50 | | **Molybdenum (Mo)** | 2.80 - 3.30 | | **Titanium (Ti)** | 0.65 - 1.15 | | **Aluminum (Al)** | 0.20 - 0.80 | | **Cobalt (Co)** | ≤ 1.00 | | **Carbon (C)** | ≤ 0.08 | | **Manganese (Mn)** | ≤ 0.35 | | **Silicon (Si)** | ≤ 0.35 | | **Sulfur (S)** | ≤ 0.015 | | **Copper (Cu)** | ≤ 0.30 | | **Boron (B)** | ≤ 0.006 | *The primary strengthening mechanism is achieved through the precipitation of coherent body-centered tetragonal gamma double prime [γ'' Ni₃Nb] phase, supplemented by gamma prime [γ' Ni₃(Al,Ti)] phase.* --- #### **Physical Properties** These properties are fundamental for design and application engineering: | Property | Metric Value | Imperial Value | | :--- | :--- | :--- | | **Density** | 8.19 g/cm³ | 0.296 lb/in³ | | **Melting Range** | 1260 - 1336 °C | 2300 - 2440 °F | | **Specific Heat (20°C)** | 435 J/kg·K | 0.104 Btu/lb·°F | | **Thermal Conductivity (20°C)** | 11.4 W/m·K | 79.1 Btu·in/hr·ft²·°F | | **Thermal Expansion Coefficient (20-100°C)** | 13.0 μm/m·°C | 7.2 μin/in·°F | | **Modulus of Elasticity** | 200 GPa | 29.0 x 10⁶ psi | | **Electrical Resistivity** | 1.25 μΩ·m | - | --- #### **Mechanical Properties** Mechanical properties are developed through solution annealing and a two-step aging treatment: **Solution Annealed + Aged Condition (AMS 5662):** * **Ultimate Tensile Strength:** ≥ 1275 MPa (185 ksi) * **Yield Strength (0.2% Offset):** ≥ 1035 MPa (150 ksi) * **Elongation:** ≥ 12% * **Reduction of Area:** ≥ 15% * **Hardness:** ≥ 35 HRC **Elevated Temperature Performance:** * **Useful Service Temperature:** Up to 700°C (1300°F) * **Creep Resistance:** Excellent up to 650°C (1200°F) * **Oxidation Resistance:** Good up to 980°C (1800°F) for short periods --- #### **International Standards** Alloy 718 is covered by numerous international standards across various product forms: **Aerospace Material Specifications (AMS):** * **AMS 5662:** Bar, forgings, and rings * **AMS 5596:** Sheet, strip, and plate * **AMS 5832:** Welding wire * **AMS 5383:** Investment castings **ASTM Standards:** * **ASTM B637:** Bar, rod, wires, and forgings * **ASTM B670:** Plate, sheet, and strip * **ASTM B805:** Forging stock **Other International Standards:** * **ISO 9724:** Nickel and nickel alloy forgings * **DIN 17752:** Nickel and nickel alloy wrought products * **GB/T 14992:** Chinese standard for superalloys --- #### **Product Applications** Alloy 718 is specified for critical components across multiple high-performance industries: **Aerospace & Defense:** * **Gas Turbine Engines:** Turbine blades, disks, shafts, casings, combustors, and afterburner components * **Rocket Engines:** Turbopump components, thrust chambers, and structural parts * **Spacecraft:** Critical structural components and fastening systems **Oil & Gas:** * **Downhole Tools:** Drill collars, subs, hangers, and blowout preventer components * **Wellhead Components:** Valves, seals, and Christmas tree parts for sour service * **Subsea Equipment:** Connectors and pressure-containing parts **Power Generation:** * **Gas Turbines:** Blades, vanes, disks, and casings * **Nuclear Reactors:** Core components and fastening systems * **Steam Turbines:** High-temperature sections **Other Applications:** * **Fasteners:** High-strength bolts, studs, and nuts * **Springs:** High-temperature and corrosion-resistant springs * **Chemical Processing:** Reactor components and heat exchangers --- #### **Key Advantages** * **Exceptional High-Temperature Strength:** Maintains mechanical properties at temperatures where most steels and alloys soften * **Excellent Fabricability:** Can be forged, machined, and welded using conventional methods * **Outstanding Corrosion Resistance:** Resists oxidation, carburization, and other forms of high-temperature degradation * **Good Weldability:** Less susceptible to post-weld heat treatment cracking compared to other precipitation-hardened nickel-based superalloys * **Superior Fatigue Resistance:** Excellent resistance to cyclic loading in both low and high-cycle fatigue regimes * **Microstructural Stability:** Retains its strengthened condition for extended periods at high temperatures **Note:** *Inconel® is a registered trademark of Special Metals Corporation, a PCC company. Alloy 718 requires specific heat treatment cycles (typically solution treatment at 954-1010°C followed by aging at 718°C for 8 hours, furnace cooling to 621°C, and holding for 8-10 hours) to achieve optimal properties. Proper processing is essential to avoid the formation of deleterious phases such as delta phase [Ni₃Nb] that can degrade mechanical properties.*

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 1780 gallon liquid totes Special package is available on request.