Alloy 825,Incoloy 825 Plate,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 Plate / UNS N08825** --- #### **1. Overview** **Alloy 825** (commercially known as **Incoloy® 825**) is a nickel-iron-chromium alloy specifically engineered with molybdenum and copper additions for exceptional corrosion resistance in aggressive environments. This datasheet focuses on the **Plate** product form, which serves as a primary material for pressure vessels, tanks, and structural components in highly corrosive service. The alloy's titanium stabilization prevents sensitization during welding, making it particularly suitable for fabricated equipment in chemical processing, oil and gas, and marine industries. The designations **Alloy 825**, **Incoloy 825 Plate**, and **UNS N08825** all refer to this corrosion-resistant nickel-base alloy in plate form. --- #### **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 Mechanical Properties:** High strength and excellent toughness * **Stabilized Against Sensitization:** Titanium addition prevents chromium carbide formation during welding --- #### **3. Chemical Composition (Weight %)** The corrosion resistance of Alloy 825 Plate 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** **Plate 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 **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 plates) --- #### **7. Applications** **Chemical Processing Industry:** * Pressure vessels for acid production and storage * Reactor vessels and mixing tanks * Heat exchanger shells and channel covers * Column and tower internal components **Oil & Gas Industry:** * Pressure vessels for sour service (H₂S environments) * Scrubber vessels and absorber towers * Process vessels in refinery service * Offshore platform components **Pollution Control:** * Flue gas desulfurization (FGD) system components * Scrubber vessels and ducting * Waste treatment tanks and vessels * Incinerator components **Marine and Offshore:** * Seawater handling equipment * Marine exhaust systems * Offshore platform structural components * Ballast water treatment systems **Other Applications:** * Nuclear waste processing equipment * Pharmaceutical processing vessels * Acid pickling tanks and equipment * Chemical transportation containers --- #### **8. Fabrication Notes** * **Welding:** Use matching filler metals (AWS A5.14 ERNiFeCr-3) for optimal corrosion resistance * **Heat Treatment:** Solution anneal at **900-980°C (1650-1800°F)** followed by rapid cooling * **Forming:** Can be cold formed using standard equipment, accounting for its work-hardening characteristics * **Cutting:** Suitable for plasma cutting, waterjet cutting, and mechanical machining * **Machining:** Requires positive rake angles and sharp tools due to work-hardening tendency --- **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 1941 gallon liquid totes Special package is available on request.