Alloy 925,Incoloy 925 ,UNS N09925,E FORU

British Specs:，American Specs:，German Specs:

### **Product Datasheet: Alloy 925 / Incoloy 925 (UNS N09925)** **Alloy 925** (commercially known as **Incoloy 925**) is a precipitation-hardenable nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium. This superalloy was specifically developed to provide exceptional resistance to sour gas (H₂S and CO₂) environments, general corrosion, and high-temperature degradation while maintaining high strength and excellent mechanical properties. It offers an optimal balance between corrosion resistance and strength for demanding oil & gas, chemical processing, and marine applications. --- #### **1. Chemical Composition** The chemical composition of Alloy 925 is carefully balanced to achieve its superior corrosion resistance and mechanical properties: | Element | Content (%) | |:---|:---| | **Nickel (Ni)** | 42.0 - 46.0 | | **Chromium (Cr)** | 19.5 - 23.5 | | **Iron (Fe)** | 22.0 min | | **Molybdenum (Mo)** | 2.5 - 3.5 | | **Copper (Cu)** | 1.5 - 3.0 | | **Titanium (Ti)** | 1.9 - 2.4 | | **Aluminum (Al)** | 0.1 - 0.5 | | **Carbon (C)** | 0.03 max | | **Manganese (Mn)** | 0.50 max | | **Silicon (Si)** | 0.50 max | | **Sulfur (S)** | 0.03 max | | **Phosphorus (P)** | 0.03 max | *Note: The combination of Nickel-Chromium provides corrosion resistance, while Titanium and Aluminum enable age-hardening through gamma prime precipitation. Molybdenum and Copper enhance resistance to reducing environments and sulfuric acid.* --- #### **2. Physical Properties** Alloy 925 exhibits the following physical properties: | Property | Value / Description | |:---|:---| | **Density** | 8.08 g/cm³ (0.292 lb/in³) | | **Melting Range** | 1370 - 1400°C (2500 - 2550°F) | | **Coefficient of Thermal Expansion** | 14.2 × 10⁻⁶/°C (20-100°C) | | **Thermal Conductivity** | 11.5 W/m·K (at 100°C) | | **Specific Heat** | 448 J/kg·K (at 100°C) | | **Modulus of Elasticity** | 196 GPa (28.4 × 10⁶ psi) | | **Magnetic Permeability** | Typically <1.005 (essentially non-magnetic) | --- #### **3. Mechanical Properties** **Typical Room Temperature Properties (Aged Condition):** | Property | Bar & Forging | Sheet & Plate | |:---|:---|:---| | **Tensile Strength** | 1035 MPa (150 ksi) min | 965 MPa (140 ksi) min | | **Yield Strength (0.2% Offset)** | 860 MPa (125 ksi) min | 760 MPa (110 ksi) min | | **Elongation** | 15% min | 15% min | | **Reduction of Area** | 35% min | - | | **Hardness (Brinell)** | 269 - 321 HB | 241 - 302 HB | **Elevated Temperature Properties:** - Maintains excellent strength up to 650°C (1200°F) - Good creep and stress rupture properties --- #### **4. Product Applications** **Oil & Gas Industry:** - **Downhole Components:** Tubing hangers, production liners, packers - **Wellhead Equipment:** Valves, stems, hangers - **Sour Service Applications:** Components exposed to H₂S and CO₂ environments - **Subsea Systems:** Christmas trees, connectors, manifolds **Chemical Processing:** - **Reactors and Vessels:** For aggressive chemical environments - **Heat Exchangers:** In corrosive service - **Pumps and Valves:** Handling sulfuric and phosphoric acids - **Distillation Columns:** Components requiring chloride stress corrosion cracking resistance **Marine & Offshore:** - **Shafting and Fasteners:** For seawater applications - **Valve Components:** In ballast and cooling systems - **Subsea Connectors:** Electrical and hydraulic systems **Other Applications:** - **Aerospace:** Engine components, fasteners - **Power Generation:** Turbine blades, fasteners - **Pollution Control:** Flue gas desulfurization systems --- #### **5. International Standards** **Material Standards:** - **UNS N09925**: Unified Numbering System designation - **ASTM B425**: Standard for Bar, Rod, and Wire - **ASTM B564**: Standard for Forgings - **ASTM B423**: Standard for Seamless Pipe and Tube - **ASTM B424**: Standard for Plate, Sheet, and Strip **Industry Specifications:** - **API 6ACRA**: Anti-corrosion alloy applications - **NACE MR0175/ISO 15156**: Suitable for sour service environments - **DNV GL**, **ABS**, **LR**: Various marine and offshore approvals **Heat Treatment Specifications:** - **Solution Annealing:** 1095-1120°C (2000-2050°F) + rapid cool - **Aging Treatment:** 620-650°C (1150-1200°F) for 8-16 hours --- #### **6. Corrosion Resistance** **Excellent Resistance To:** - Sulfide stress cracking (SSC) - Chloride stress corrosion cracking (ClSCC) - Pitting and crevice corrosion - General corrosion in acids and alkalis - Erosion-corrosion in flowing media **Environmental Limitations:** - Not recommended for strongly oxidizing acids (nitric acid) - Limited resistance to hot, wet hydrofluoric acid --- #### **7. Key Advantages** * **Superior SSC Resistance:** Excellent performance in sour gas environments containing H₂S * **High Strength:** Maintains mechanical properties at elevated temperatures * **Versatile Fabricability:** Good weldability and formability in annealed condition * **Broad Chemical Resistance:** Performs well in both oxidizing and reducing environments * **Long Service Life:** Exceptional resistance to stress corrosion cracking and pitting * **Industry Acceptance:** Meets major oil & gas and chemical industry standards --- #### **8. Manufacturing Considerations** **Machining:** - More difficult than austenitic stainless steels but machinable with proper techniques - Recommended use of carbide tools with positive rake angles - Adequate cooling and lubrication required **Welding:** - Can be welded using GTAW, GMAW, and SMAW processes - Use matching filler metals (ERNiFeCr-1 or equivalent) - Post-weld heat treatment typically required for optimum properties **Forming:** - Best formed in the solution-annealed condition - Requires more power than stainless steels due to higher strength Alloy 925 represents a premium corrosion-resistant alloy solution for the most demanding applications in oil & gas production, chemical processing, and marine engineering where both high strength and exceptional corrosion resistance are required.

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 2001 gallon liquid totes Special package is available on request.