Altemp 625 Nickel-Base Superalloy, UNS N06625,1

### **Product Datasheet: Altemp 625 / INCONEL® 625 (UNS N06625)** **A Nickel-Chromium-Molybdenum-Niobium Superalloy for Extreme Environments** --- #### **1. Overview** **Altemp 625**, commercially known as **INCONEL® 625**, is a nickel-chromium-molybdenum-niobium superalloy designed to exhibit exceptional strength and toughness over a wide temperature range, from cryogenic temperatures to 980°C (1800°F). The alloy derives its strength from the solid solution hardening effects of molybdenum and niobium in the nickel-chromium matrix, without requiring precipitation hardening treatments. This alloy offers outstanding resistance to a wide range of severe corrosive environments, including pitting, crevice corrosion, and oxidation. Its excellent fabrication characteristics and weldability make it particularly valuable for demanding applications in aerospace, marine, and chemical processing industries. --- #### **2. Chemical Composition (Typical Weight %)** | Element | Content (%) | Role in the Alloy | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance (~58.0) | Forms the corrosion-resistant matrix | | **Chromium (Cr)** | ~20.0-23.0 | Provides oxidation and corrosion resistance | | **Molybdenum (Mo)** | ~8.0-10.0 | Enhances pitting and crevice corrosion resistance | | **Niobium (Nb)** | ~3.15-4.15 | Provides strengthening through carbide formation | | **Iron (Fe)** | ≤ 5.0 | Residual element | | **Aluminum (Al)** | ≤ 0.40 | Residual element | | **Titanium (Ti)** | ≤ 0.40 | Residual element | | **Carbon (C)** | ≤ 0.10 | Controlled for carbide formation | | **Manganese (Mn)** | ≤ 0.50 | Residual element | --- #### **3. Physical Properties (Typical)** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.44 g/cm³ (0.305 lb/in³) | | **Melting Range** | 1290-1350 °C (2350-2460 °F) | | **Thermal Expansion Coefficient** | 12.8 μm/m·°C (20-100°C) | | **Thermal Conductivity** | 9.8 W/m·K (at 100°C) | | **Modulus of Elasticity** | 207 GPa (30.0×10⁶ psi) | | **Electrical Resistivity** | 1.29 μΩ·m | | **Magnetic Permeability** | ~1.001 (essentially non-magnetic) | --- #### **4. Mechanical Properties** **Room Temperature (Annealed Condition):** * **Tensile Strength**: 830 MPa (120 ksi) min * **Yield Strength (0.2% Offset)**: 415 MPa (60 ksi) min * **Elongation**: 30% min **Elevated Temperature Performance:** * Excellent strength retention up to 980°C (1800°F) * Good creep and stress-rupture properties * Maintains oxidation resistance at high temperatures **Cryogenic Performance:** * Excellent toughness and ductility at sub-zero temperatures --- #### **5. Corrosion Resistance** Altemp 625 demonstrates exceptional corrosion resistance in diverse environments: * **Pitting and Crevice Corrosion**: Excellent resistance in chloride-ion containing solutions * **Oxidizing Environments**: Superior performance in nitric and phosphoric acids * **Marine Applications**: Outstanding resistance to seawater and marine atmospheres * **High-Temperature Oxidation**: Excellent scaling resistance up to 980°C * **Stress Corrosion Cracking**: Highly resistant in chloride environments --- #### **6. Product Applications** **Aerospace Industry:** * Jet engine components and exhaust systems * Ducting systems and thrust reversers * Engine mounts and firewall seals **Marine Engineering:** * Propeller blades and submarine fittings * Seawater heat exchangers and condenser tubes * Marine shafting and fasteners **Chemical Processing:** * Reactor vessels and heat exchanger tubing * Process piping systems and agitators * Flue gas desulfurization systems **Power Generation:** * Gas turbine ducting and expansion joints * Heat recovery systems * Nuclear reactor core components **Other Applications:** * Pollution control equipment * Oil and gas downhole components * Specialized chemical transportation --- #### **7. International Standards** * **UNS**: N06625 * **DIN/Werkstoff Nr.**: 2.4856 * **ASTM/ASME Specifications**: * **ASTM B-443 / ASME SB-443**: Plate, Sheet, and Strip * **ASTM B444**: Pipe and Tube * **ASTM B446**: Rod and Bar * **Aerospace Material Specification**: * **AMS 5599**: Sheet, Strip, and Plate * **Additional Certifications**: * ASME Boiler and Pressure Vessel Code * NACE MR0175/ISO 15156 * ISO 6208 for wrought nickel alloys * Various military and nuclear standards --- **Technical Note:** The information provided represents typical values and characteristics. Actual properties may vary based on manufacturing processes, heat treatment, and specific product form. For critical applications, always consult the most recent edition of relevant material specifications and manufacturer's technical data. *INCONEL is a registered trademark of Special Metals Corporation. Altemp 625 is understood to be a related designation for this alloy composition.*

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 3382 gallon liquid totes Special package is available on request.