INCOLOY Alloy 825,，1

### **Product Introduction: INCOLOY® Alloy 825** **INCOLOY® Alloy 825** is a nickel-iron-chromium alloy with additions of molybdenum and copper, designed to provide exceptional corrosion resistance in a wide range of aggressive environments. This austenitic alloy is particularly effective in resisting corrosion in both oxidizing and reducing acids, and exhibits excellent resistance to stress corrosion cracking and pitting in chloride-containing media. The alloy's balanced composition ensures superior performance in sulfuric and phosphoric acid environments, while its nickel content provides resistance to chloride-ion stress-corrosion cracking. It is widely recognized for its versatility and reliability in chemical processing, pollution control, and oil and gas applications. --- ### **Chemical Composition** The chemical composition is carefully balanced for optimal corrosion resistance: | Element | Content (%) | |---------|-------------| | **Nickel (Ni)** | 38.0 - 46.0 | | **Chromium (Cr)** | 19.5 - 23.5 | | **Iron (Fe)** | Balance | | **Molybdenum (Mo)** | 2.5 - 3.5 | | **Copper (Cu)** | 1.5 - 3.0 | | **Titanium (Ti)** | 0.6 - 1.2 | | **Carbon (C)** | 0.05 max | | **Manganese (Mn)** | 1.0 max | | **Silicon (Si)** | 0.5 max | | **Sulfur (S)** | 0.03 max | | **Aluminum (Al)** | 0.2 max | --- ### **Physical Properties** INCOLOY Alloy 825 exhibits typical physical properties of nickel-iron-chromium alloys: | Property | Value | |----------|-------| | **Density** | 8.14 g/cm³ | | **Melting Point** | 1370-1400 °C | | **Thermal Conductivity** | 10.8 W/m·K (at 20°C) | | **Electrical Resistivity** | 1.12 μΩ·m | | **Modulus of Elasticity** | 196 GPa | | **Coefficient of Thermal Expansion** | 14.0 μm/m·°C (20-100°C) | | **Specific Heat Capacity** | 440 J/kg·K | | **Magnetic Permeability** | <1.01 (essentially non-magnetic) | --- ### **Mechanical Properties** The alloy demonstrates excellent mechanical properties across temperature ranges: **Room Temperature Properties (Annealed Condition):** - **Tensile Strength:** 620-850 MPa - **Yield Strength (0.2% Offset):** 240-450 MPa - **Elongation:** 30-60% - **Hardness:** 150-210 HB **Elevated Temperature Performance:** - **Maximum Service Temperature:** 540°C (1000°F) - **Good strength retention at elevated temperatures** - **Excellent thermal stability** --- ### **Heat Treatment** **Standard Heat Treatment:** - **Annealing Temperature:** 925-980°C (1700-1800°F) - **Soaking Time:** 1-2 hours per inch of thickness - **Cooling:** Rapid air cooling or water quenching **Stress Relieving:** - Recommended after severe cold working - Temperature: 540-650°C (1000-1200°F) --- ### **Key Characteristics & Advantages** 1. **Exceptional Corrosion Resistance** - Excellent resistance to sulfuric and phosphoric acids - Good resistance to nitric acid and other oxidizing agents - Superior pitting and crevice corrosion resistance 2. **Versatile Environmental Performance** - Resists both oxidizing and reducing environments - Excellent resistance to chloride-ion stress corrosion cracking - Good performance in alkaline and acidic salt solutions 3. **Excellent Fabricability** - Good weldability using common techniques - Can be hot and cold worked using standard methods - Good machinability in annealed condition 4. **Stable Microstructure** - Titanium stabilization prevents sensitization - Resists carbide precipitation during welding - Maintains properties in long-term service --- ### **Product Applications** **Chemical Processing Industry:** - Reactors and pressure vessels - Heat exchangers and condensers - Piping systems and valves - Acid production equipment **Oil and Gas Industry:** - Downhole components - Production tubing - Wellhead equipment - Process piping in refineries **Pollution Control:** - Flue gas desulfurization systems - Scrubbers and ducting - Waste water treatment equipment - Acid waste handling systems **Other Applications:** - Nuclear fuel reprocessing - Acid picking equipment - Seawater handling systems - Pharmaceutical processing equipment --- ### **International Standards** INCOLOY Alloy 825 is recognized under major international specifications: | Standard Type | Standard Number | Product Form | |---------------|-----------------|--------------| | **ASTM** | B424 | Plate, Sheet, and Strip | | **ASTM** | B423 | Seamless Pipe and Tube | | **ASTM** | B425 | Bar and Billet | | **ASTM** | B704/B705 | Welded Tube | | **ASME** | SB-424, SB-423 | Code Cases | | **DIN** | 2.4858 | Material Number | | **UNS** | N08825 | Unified Numbering System | | **EN** | NiCr21Mo | European Standard | --- ### **Summary** **INCOLOY Alloy 825** is a versatile nickel-iron-chromium alloy that offers outstanding corrosion resistance in a wide variety of aggressive environments. Its balanced composition provides exceptional performance in both oxidizing and reducing media, with particular effectiveness against sulfuric and phosphoric acids. The alloy's resistance to chloride-ion stress corrosion cracking, combined with its excellent fabricability and weldability, makes it a preferred choice for critical applications in chemical processing, oil and gas, and pollution control industries. Certification to major international standards including ASTM, ASME, and DIN specifications ensures consistent quality and reliability, providing engineers with a proven material solution for demanding corrosive environments where performance and longevity are essential requirements.

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 3324 gallon liquid totes Special package is available on request.