Alloy 825,Incoloy 825 Sheet,UNS N08825,E FORU

British Specs:BS 3072 BS 3073 BS 3074 BS 3075 BS 3076 NA16，American Specs:ASTM B425 ASTM B424 ASTM B163 (Tube *)，German Specs:WS 2.4858

### **Technical Datasheet: Alloy 825 / Incoloy 825 Sheet / UNS N08825** --- #### **1. Overview** **Alloy 825** (commercially known as **Incoloy® 825**) is a nickel-iron-chromium superalloy specifically engineered with molybdenum and copper additions for exceptional corrosion resistance in aggressive environments. This datasheet focuses on the **Sheet** product form, which is widely used for fabricating tanks, vessels, and structural components where corrosion resistance is paramount. The alloy's titanium stabilization prevents sensitization during welding operations, making it ideal for fabricated equipment across chemical processing, oil and gas, and marine industries. The designations **Alloy 825**, **Incoloy 825 Sheet**, and **UNS N08825** all refer to this corrosion-resistant nickel-base alloy in sheet form, typically supplied in thicknesses up to 6mm. --- #### **2. Key Characteristics** * **Excellent General Corrosion Resistance:** Outstanding performance in both oxidizing and reducing environments * **Superior Acid Resistance:** Exceptional resistance to sulfuric acid, phosphoric acid, and other reducing acids * **Excellent Stress Corrosion Cracking (SCC) Resistance:** Highly resistant to chloride-induced SCC * **Pitting and Crevice Corrosion Resistance:** Enhanced by molybdenum content (2.5-3.5%) * **Good Formability and Weldability:** Suitable for complex fabrications * **Stabilized Against Sensitization:** Titanium addition prevents chromium carbide formation during welding --- #### **3. Chemical Composition (Weight %)** The corrosion resistance of Alloy 825 Sheet is ensured by its precise chemical balance. | Element | Minimum (%) | Maximum (%) | Key Function | | :--- | :--- | :--- | :--- | | **Nickel (Ni)** | 38.0 | 46.0 | Provides fundamental corrosion resistance in reducing environments | | **Chromium (Cr)** | 19.5 | 23.5 | Confers resistance to oxidizing environments | | **Iron (Fe)** | 22.0 min | Balance | Base element of the alloy | | **Molybdenum (Mo)** | 2.5 | 3.5 | Enhances pitting and crevice corrosion resistance | | **Copper (Cu)** | 1.5 | 3.0 | Provides resistance to reducing acids, particularly sulfuric acid | | **Titanium (Ti)** | 0.6 | 1.2 | Stabilizes against sensitization by forming titanium carbides | | **Carbon (C)** | - | 0.05 | Kept low to minimize carbide formation | | **Manganese (Mn)** | - | 1.00 | - | | **Sulfur (S)** | - | 0.03 | - | | **Silicon (Si)** | - | 0.05 | - | --- #### **4. Physical Properties (Typical)** | Property | Value | | :--- | :--- | | **Density** | 8.14 g/cm³ (0.294 lb/in³) | | **Melting Range** | 1370 - 1400 °C (2500 - 2550 °F) | | **Specific Heat (20°C)** | 440 J/kg·K | | **Thermal Conductivity** | 10.8 W/m·K (at 100°C) | | **Mean Coefficient of Thermal Expansion** | 14.0 μm/m·K (20 - 100°C) | | **Electrical Resistivity** | 1.12 μΩ·m | | **Modulus of Elasticity** | 196 GPa (28.4 x 10⁶ psi) | --- #### **5. Mechanical Properties (Typical for Annealed Condition)** * **Tensile Strength:** 655 MPa (95 ksi) min * **Yield Strength (0.2% Offset):** 275 MPa (40 ksi) min * **Elongation:** 30% min * **Hardness:** Rb 90 max --- #### **6. International Standards & Specifications** **Sheet Products:** * **ASTM B424 / ASME SB424:** Standard Specification for UNS N08825 Plate, Sheet, and Strip * **ASTM B906:** Standard Specification for General Requirements for Flat-Rolled Nickel and Nickel Alloys Plate, Sheet, and Strip * **ASME Section II:** Material Specifications * **EN 10095:** Heat resisting steels and nickel alloys **Dimensional Standards:** * **ASTM B424M:** Metric equivalent specification * **ASTM B906:** General requirements for dimensional tolerances **General Material Standards:** * **UNS:** N08825 * **EN (Euronorm):** EN 2.4858 (NiCr21Mo) * **DIN:** 2.4858 * **ISO:** 6207 (Nickel alloy sheets) --- #### **7. Applications** **Chemical Processing Industry:** * Lining systems for tanks and vessels * Heat exchanger components * Reaction vessel fabrication * Acid storage tank construction **Oil & Gas Industry:** * Pressure vessel components * Scrubber system fabrication * Process equipment lining * Offshore platform components **Pollution Control:** * Flue gas desulfurization (FGD) system ducting * Scrubber vessel construction * Waste treatment equipment * Environmental protection systems **Marine and Offshore:** * Seawater system components * Marine exhaust systems * Offshore platform modules * Ballast water treatment equipment **Other Applications:** * Pharmaceutical processing equipment * Food processing machinery * Pulp and paper industry equipment * Waste incineration plants --- #### **8. Fabrication Notes** * **Welding:** Use matching filler metals (AWS A5.14 ERNiFeCr-3) for GTAW, GMAW processes * **Heat Treatment:** Solution anneal at **900-980°C (1650-1800°F)** followed by rapid cooling * **Forming:** Excellent cold forming characteristics; can be deep drawn, stretch formed, and roll formed * **Cutting:** Suitable for laser cutting, plasma cutting, waterjet cutting, and shearing * **Surface Finish:** Available in various finishes including 2B, No. 1, and polished finishes --- **Disclaimer:** This technical information is for reference purposes. For critical applications, always consult the specific material certification and the latest version of the relevant standards. Actual properties may vary depending on manufacturing processes and heat treatment.

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 1942 gallon liquid totes Special package is available on request.