INCONEL Alloy 751,Nickel-Chromium Alloy; UNS N07751，1

### **Product Introduction: INCONEL® Alloy 751 (UNS N07751)** **INCONEL® Alloy 751** is a precipitation-hardenable nickel-chromium alloy designed to provide high strength and excellent corrosion resistance at temperatures up to 1300°F (705°C). Its composition is similar to INCONEL Alloy X-750 but is specifically controlled to optimize properties for critical applications such as jet engine components, particularly exhaust valves in internal combustion engines. The alloy is strengthened by the precipitation of gamma prime [Ni₃(Al, Ti)] phase through a precise heat treatment sequence involving solution annealing and aging. This process gives Alloy 751 an outstanding combination of high tensile and creep-rupture strength, excellent fatigue resistance, and good oxidation resistance, making it a reliable choice for high-stress components in aerospace and industrial sectors. --- ### **International Standards & Material Equivalents** INCONEL Alloy 751 is covered by several key international specifications, particularly in the aerospace industry. | Standard Type | Standard Number | Designation / Product Form | | :--- | :--- | :--- | | **UNS (USA)** | **N07751** | **INCONEL Alloy 751** | | **AMS (Aerospace)** | AMS 5870 | Sheet, Strip, and Plate | | **AMS (Aerospace)** | AMS 5871 | Bar and Wire (Solution Heat Treated) | | **AMS (Aerospace)** | AMS 5872 | Bar and Wire (Solution Heat Treated and Aged) | | **ASTM** | B637 | Rod, Bar, and Forgings | | **ASME** | SB-637 | Pressure Vessel Code Edition | | **DIN (Germany)** | 17742 | NiCr15Fe7TiAl | | **Werkstoff Nr.** | **2.4699** | **2.4699** | > **Note:** INCONEL® is a registered trademark of Special Metals Corporation. The primary identifier is **UNS N07751**. --- ### **Chemical Composition** The composition is carefully balanced to achieve optimal precipitation hardening response while maintaining good corrosion resistance and high-temperature stability. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 70.0 min. | | **Chromium (Cr)** | 14.0 - 17.0 | | **Iron (Fe)** | 5.0 - 9.0 | | **Titanium (Ti)** | 2.00 - 2.60 | | **Aluminum (Al)** | 0.90 - 1.50 | | **Niobium (Nb)** | 0.75 - 1.25 | | **Manganese (Mn)** | 1.00 max. | | **Silicon (Si)** | 0.50 max. | | **Copper (Cu)** | 0.50 max. | | **Carbon (C)** | 0.08 max. | | **Sulfur (S)** | 0.008 max. | --- ### **Physical Properties** Alloy 751 exhibits physical properties suitable for high-temperature applications requiring thermal cycling and structural integrity. | Property | Value | | :--- | :--- | | **Density** | 8.28 g/cm³ (0.299 lb/in³) | | **Melting Point** | 1390 - 1425 °C (2535 - 2600 °F) | | **Thermal Conductivity** | 12.3 W/m·K (at 20°C) | | **Electrical Resistivity** | 1.22 μΩ·m (at 20°C) | | **Modulus of Elasticity** | 214 GPa (31 x 10⁶ psi) | | **Coefficient of Thermal Expansion** | 13.1 μm/m·°C (20-100°C) | | **Magnetic Response** | Essentially non-magnetic | --- ### **Mechanical Properties (Typical for Aged Condition - AMS 5872)** The alloy develops its high strength through solution treatment followed by precipitation hardening (aging). | Property | Value (Room Temperature, Aged) | | :--- | :--- | | **Tensile Strength** | 1103 - 1241 MPa (160 - 180 ksi) | | **Yield Strength (0.2% Offset)** | 758 - 896 MPa (110 - 130 ksi) | | **Elongation** | 20% - 25% | | **Hardness (Rockwell C)** | 30 - 38 HRC | --- ### **Key Characteristics & Advantages** 1. **High Strength at Elevated Temperatures:** Maintains excellent tensile, creep, and rupture strength up to 705°C (1300°F). 2. **Excellent Fatigue Resistance:** Performs well under cyclic loading conditions, making it suitable for rotating components. 3. **Good Oxidation and Corrosion Resistance:** Resists oxidation and corrosion in various environments, with particular resistance to chloride-ion stress-corrosion cracking. 4. **Outstanding Relaxation Resistance:** Maintains load under sustained stress at high temperatures, ideal for spring applications. 5. **Controlled Microstructure:** Specifically processed to maintain stability and prevent embrittlement during long-term high-temperature service. --- ### **Product Applications** INCONEL Alloy 751 is widely used in demanding applications where high temperature strength and reliability are critical. * **Aerospace & Jet Engines:** * **Turbine blades,** disks, and seals * **Afterburner components** and combustion liners * **Fasteners,** bolts, and studs * **Springs** and bellows for high-temperature service * **Automotive & Racing:** * **Exhaust valves** and valve springs for high-performance engines * **Turbocharger components** * **Industrial Gas Turbines:** * **Turbine blades** and wheels * **Bolting** and other high-strength components * **Nuclear Power:** * **Reactor core components** * **Fasteners** and springs for nuclear service * **Other Applications:** * **Hot-work tooling** and forming equipment * **Test machine components** requiring high strength-to-weight ratio ### **Summary** **INCONEL Alloy 751 (UNS N07751)** is a premium, precipitation-hardenable nickel-chromium alloy that provides an exceptional combination of **high strength, excellent fatigue resistance, and good corrosion resistance at elevated temperatures**. Its specifically controlled composition and heat treatment make it particularly suitable for critical applications in aerospace, automotive, and power generation industries. Governed by standards such as **AMS 5870** and **ASTM B637**, it remains a preferred material for turbine components, exhaust valves, and high-temperature fasteners where reliability under extreme conditions is paramount. The alloy's balanced properties make it especially valuable for applications requiring long-term stability under high stress and temperature.

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 3304 gallon liquid totes Special package is available on request.