Alloy 722,Inconel 722,UNS N07722,EFORU

### **Technical Datasheet: Alloy 722 (Inconel 722, UNS N07722)** 

 **Introduction** Alloy 722 is a precipitation-hardenable nickel-chromium-iron alloy known for its exceptional high-temperature strength, superior creep resistance, and excellent oxidation resistance. While sharing a similar base with Alloy 718, Alloy 722 is distinguished by its higher chromium content and a carefully balanced addition of titanium and aluminum, resulting in a greater volume fraction of the strengthening gamma prime (γ') phase [Ni₃(Al,Ti)]. This makes it a premier choice for applications requiring long-term stability and strength at temperatures exceeding the effective range of Alloy 718, typically up to around 815°C (1500°F). 

 **Key Features** *   

**Superior High-Temperature Strength:** Offers higher tensile, creep, and rupture strength than Alloy 718 at temperatures above 650°C (1200°F). *   

**Excellent Oxidation Resistance:** High chromium content provides outstanding resistance to scaling and oxidation in air and other aggressive atmospheres. *   

**Outstanding Creep-Rupture Life:** Designed to withstand prolonged exposure under stress at elevated temperatures. *   

**Good Microstructural Stability:** Resists the formation of detrimental phases during long-term aging, ensuring property retention. *   

**Good Fabricability:** Can be forged, hot-worked, and machined using standard techniques for high-performance superalloys. 

Chemical Composition (Weight %)** The typical composition of Alloy 722 is specified in various international standards. The following is a representative range:

| Element | Minimum (%) | Maximum (%) | 

| :--- | :--- | :--- | 

 **Nickel (Ni)** | Balance | - | 

| **Chromium (Cr)** | 14.0 | 17.0 | 

| **Iron (Fe)** | 5.0 | 9.0 | 

| **Molybdenum (Mo)** | 2.75 | 3.25 | 

| **Titanium (Ti)** | 4.75 | 5.25 | 

| **Aluminum (Al)** | 2.50 | 3.00 | 

| **Cobalt (Co)** | - | 1.00 | 

| **Carbon (C)** | 0.04 | 0.08 | 

| **Manganese (Mn)** | - | 0.25 | 

| **Silicon (Si)** | - | 0.25 | 

| **Copper (Cu)** | - | 0.10 | 

| **Boron (B)** | 0.003 | 0.010 | 

| **Zirconium (Zr)** | 0.02 | 0.08 | 

 *The primary strengthening mechanism is precipitation hardening via the gamma prime (γ') phase [Ni₃(Al,Ti)]. The high combined (Ti+Al) content is key to its elevated temperature performance.

2. Physical Properties** 

 | Property | Value | 

| :--- | :--- | 

| **Density** | 7.92 g/cm³ (0.286 lb/in³) | 

| **Melting Range** | ~ 1385 - 1425 °C (~ 2525 - 2600 °F) | 

| **Specific Heat (20°C)** | ~ 450 J/kg·K | 

| **Thermal Conductivity (20°C)** | ~ 12.0 W/m·K | 

| **Mean Coefficient of Thermal Expansion (20-100°C)** | ~ 12.6 µm/m·°C | 

| **Modulus of Elasticity (Young's Modulus)** | ~ 214 GPa (31.0 x 10⁶ psi) | 

3. Mechanical Properties 

(Typical for Solution Treated and Aged Condition)** 

 Properties are highly dependent on the specific heat treatment cycle. The following are typical values for bar products. **Room Temperature:** *   

**Tensile Strength:** ≥ 1240 MPa (180 ksi) *   

**Yield Strength (0.2% Offset):** ≥ 895 MPa (130 ksi) *   

**Elongation:** ≥ 15% **At 730°C (1350°F):** *   

**Tensile Strength:** ~ 895 MPa (130 ksi) *   

**Yield Strength (0.2% Offset):** ~ 760 MPa (110 ksi) *   

**Creep-Rupture Strength (1000 hrs to rupture):** Significantly higher than Alloy 718 at equivalent temperatures. 

4. International Standards** 

Alloy 722 is covered by several key aerospace and industrial specifications. It is less universally standardized than Alloy 718 and is often procured to proprietary or customer-specific requirements

| Product Form | Standard Examples | 

| :--- | :--- | 

| **Bar, Wire, Forgings** | **AMS 7200** (Forging Bar and Wire), **AMS 7201** (Ring Forging) | 

| **Billet & Reforging Stock** | **AMS 7202** | 

| **European Standard** | **No common EN designation equivalent.

** Often specified by proprietary names or UNS number. | 

| **Unified Numbering System** | **UNS N07722** | -

5. Product Applications** 

 Alloy 722 is a specialized alloy used in the most demanding high-temperature rotating components, primarily in aerospace and industrial gas turbines. *   

**Aerospace & Jet Engines:**    *   

**Turbine Rotor Blades and Buckets**    *   

**Turbine Disks (Wheels)** and Shafts    *   

**Compressor Disks** and Rotors for high-pressure stages    *   

**Spacers** and Seals *   

**Industrial Gas Turbines (IGT):**    *   

**Turbine Blades and Vanes**    *   

**Rotors and Disks**    *   

Combustion chamber components *   

**Other High-Temperature Applications:**    *   

Fasteners and bolts for extreme service    *   

Nuclear reactor core components 

*Conclusion** 

Alloy 722 (Inconel 722, UNS N07722) is a high-performance, gamma-prime strengthened superalloy engineered for superior mechanical properties at temperatures where alloys like 718 begin to weaken. Its optimized chemistry provides an excellent combination of high strength, creep resistance, and oxidation stability, making it a critical material for advanced turbine engine components. While less common than Alloy 718, it serves a vital role in pushing the boundaries of performance and efficiency in high-temperature engineering.

Packing of Alloy 722 (Inconel 722, UNS N07722) 

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 1637 gallon liquid totes Special package is available on request.