INCONEL Alloy 718,IN718, INCONEL 718, AFNOR NC 19 Fe Nb, UNS N07718; ，1

### **Product Introduction: INCONEL® Alloy 718 (UNS N07718)** **INCONEL® Alloy 718** is a premier, precipitation-hardenable nickel-chromium alloy renowned for its exceptional combination of high strength, excellent corrosion resistance, and outstanding weldability. It is strengthened by the addition of niobium and molybdenum, which form coherent gamma double prime (γ") precipitates during a precise aging heat treatment. A key advantage of Alloy 718 is that it can be welded in the fully aged condition without being susceptible to post-weld strain-age cracking, a common issue with other high-temperature superalloys. This alloy maintains high yield, tensile, and creep-rupture strength up to about 1300°F (700°C) and exhibits excellent oxidation resistance. Its superior manufacturability and reliability have made it one of the most widely used superalloys in the aerospace and oil & gas industries. --- ### **International Standards & Material Equivalents** INCONEL Alloy 718 is covered by a vast array of international specifications, reflecting its global importance. | Standard Type | Standard Number | Designation / Product Form | | :--- | :--- | :--- | | **UNS (USA)** | **N07718** | **INCONEL Alloy 718** | | **AFNOR (France)** | **NC 19 Fe Nb** | **NC 19 Fe Nb** | | **AMS (Aerospace)** | AMS 5662 | Bar, Forgings, and Ring | | **AMS (Aerospace)** | AMS 5596 | Sheet, Strip, and Plate | | **AMS (Aerospace)** | AMS 5383 | Investment Castings | | **ASTM** | B637 | Rod, Bar, and Forgings | | **ASTM** | B670 | Plate | | **DIN (Germany)** | 17742 | NiCr19NbMo | | **Werkstoff Nr.** | **2.4668** | **2.4668** | | **ISO** | 15156-3 | MR0175 (For sour service) | > **Note:** INCONEL® is a registered trademark of Special Metals Corporation. The primary identifiers are **UNS N07718**, **AFNOR NC 19 Fe Nb**, and **Werkstoff 2.4668**. --- ### **Chemical Composition** The composition is precisely controlled to achieve its unique strengthening mechanism and properties. | 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)** | 1.0 max. | | **Carbon (C)** | 0.08 max. | | **Manganese (Mn)** | 0.35 max. | | **Silicon (Si)** | 0.35 max. | | **Copper (Cu)** | 0.30 max. | --- ### **Physical Properties** Alloy 718 exhibits physical properties suitable for high-stress applications across a wide temperature range. | Property | Value | | :--- | :--- | | **Density** | 8.19 g/cm³ (0.296 lb/in³) | | **Melting Point** | 1260 - 1336 °C (2300 - 2440 °F) | | **Thermal Conductivity** | 11.4 W/m·K (at 20°C) | | **Electrical Resistivity** | 1.25 μΩ·m (at 20°C) | | **Modulus of Elasticity** | 204 GPa (29.5 x 10⁶ psi) | | **Coefficient of Thermal Expansion** | 13.0 μm/m·°C (20-100°C) | | **Magnetic Response** | Essentially non-magnetic | --- ### **Mechanical Properties (Typical for Solution and Aged Condition - AMS 5662)** The alloy achieves its maximum strength through a solution treatment followed by a two-step aging process. | Property | Value (Room Temperature, Aged) | | :--- | :--- | | **Tensile Strength** | 1310 MPa (190 ksi) | | **Yield Strength (0.2% Offset)** | 1100 MPa (160 ksi) | | **Elongation** | 20% | | **Hardness (Rockwell C)** | 36 - 44 HRC | --- ### **Key Characteristics & Advantages** 1. **High Strength up to 700°C:** Offers an outstanding balance of high tensile, yield, and creep-rupture strength at elevated temperatures. 2. **Excellent Weldability with No Post-Weld Cracking:** Its primary advantage over many other age-hardenable nickel alloys. It can be welded in the aged condition without subsequent cracking. 3. **Superior Corrosion Resistance:** Resists oxidation, pitting, and crevice corrosion in a wide range of environments, including air, fresh water, seawater, and alkaline media. 4. **Good Fatigue Resistance and Fracture Toughness:** Performs well under cyclic loading conditions. 5. **Excellent Fabricability:** Can be readily forged, formed, and machined, though it is a strong, hard material requiring appropriate tooling and techniques. --- ### **Product Applications** INCONEL Alloy 718 is a critical material in several high-performance industries. * **Aerospace & Jet Engines:** * **Turbine blades, discs, shafts, and spacers.** * **Compressor components,** casings, and afterburner parts. * **Rocket motors,** thrust chambers, and cryogenic components. * **Oil & Gas (Sour Service):** * **Downhole tools,** wellhead components, and Christmas trees. * **Subsea equipment,** fasteners, and valve components resistant to sulfide stress cracking. * **Power Generation:** * Bolting, blades, and turbine wheels in gas turbines. * Components for nuclear reactors. * **Other Applications:** * High-strength fasteners. * Plastic extrusion barrels and high-wear components. ### **Summary** **INCONEL Alloy 718 (UNS N07718 / AFNOR NC 19 Fe Nb)** is a foundational precipitation-hardenable superalloy that sets the standard for high-strength applications up to 700°C. Its unique **niobium-strengthened composition** grants it an unparalleled combination of extreme mechanical properties, excellent corrosion resistance, and—most importantly—**superior weldability without post-weld heat treatment cracking**. Governed by a comprehensive set of standards like **AMS 5662**, it remains the most widely used superalloy in the world for critical components in aerospace propulsion, oil & gas extraction, and power generation, where performance and 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 3302 gallon liquid totes Special package is available on request.