Alloy G-3,INCO G-3,，EFORU

### **Alloy G-3 / INCO G-3 (UNS N06985) - Technical Datasheet** --- #### **1. Overview** **Alloy G-3**, also known as **INCO G-3**, is a nickel-chromium-iron-molybdenum alloy designed to offer superior corrosion resistance in a wide range of aggressive media. As an improved version of earlier G-type alloys, it provides enhanced resistance to sulfuric and phosphoric acids, along with excellent pitting and crevice corrosion resistance. The alloy maintains good fabricability and weldability, making it suitable for demanding chemical process applications. --- #### **2. Chemical Composition (Weight %)** The composition is optimized for maximum corrosion resistance. | Element | Content (%) | Role & Benefit | |---------|-------------|----------------| | **Nickel (Ni)** | Balance | Base element providing fundamental corrosion resistance | | **Chromium (Cr)** | 21.0 - 23.5 | Resistance to oxidizing environments | | **Iron (Fe)** | 18.0 - 21.0 | Controlled for cost and corrosion balance | | **Molybdenum (Mo)** | 6.0 - 8.0 | Resistance to reducing environments and pitting corrosion | | **Copper (Cu)** | 1.5 - 2.5 | Enhances resistance to sulfuric acid | | **Cobalt (Co)** | ≤ 5.0 | Controlled residual element | | **Tungsten (W)** | ≤ 1.5 | Solid solution strengthening | | **Manganese (Mn)** | ≤ 1.0 | Deoxidizer and workability agent | | **Niobium (Nb)** | 0.50 max | Stabilization against sensitization | | **Silicon (Si)** | ≤ 1.0 | Deoxidizer and fluidity agent | | **Carbon (C)** | ≤ 0.015 | Minimally controlled to prevent carbide precipitation | | **Sulfur (S)** | ≤ 0.030 | Controlled impurity | --- #### **3. Physical Properties** The physical properties support use in corrosive environments. | Property | Value | |----------|-------| | **Density** | 8.28 g/cm³ (0.299 lb/in³) | | **Melting Point** | 1325-1370°C (2415-2500°F) | | **Specific Heat (20°C)** | 430 J/kg·K | | **Thermal Conductivity** | 10.5 W/m·K (at 20°C) | | **Mean Coefficient of Thermal Expansion** | 13.5 × 10⁻⁶/°C (20-300°C) | | **Electrical Resistivity** | 1.15 μΩ·m | | **Modulus of Elasticity** | 200 GPa (29.0 × 10⁶ psi) | | **Magnetic Permeability** | Essentially non-magnetic | --- #### **4. Mechanical Properties** The alloy offers good mechanical strength and ductility. **Annealed Condition:** | Property | Value | |----------|-------| | **Tensile Strength** | 690-795 MPa (100-115 ksi) | | **Yield Strength (0.2% Offset)** | 310-415 MPa (45-60 ksi) | | **Elongation** | 40-50% | | **Hardness** | 80-95 HRB | **Elevated Temperature Properties (400°C/750°F):** | Property | Value | |----------|-------| | **Tensile Strength** | 550 MPa (80 ksi) | | **Yield Strength** | 275 MPa (40 ksi) | | **Creep Strength** | 180 MPa (26 ksi) | --- #### **5. Product Applications** **Alloy G-3** serves in severe corrosive environments: - **Chemical Processing:** - Sulfuric acid pickling systems - Phosphoric acid production equipment - Acid recovery evaporators - Chemical reactor vessels - **Petrochemical Industry:** - Downhole tubing in sour gas wells - Heat exchangers in refinery service - Piping systems for corrosive hydrocarbons - Pressure vessels in H₂S environments - **Pollution Control:** - Flue gas desulfurization systems - Scrubbers for acid gas removal - Waste water treatment equipment - Chemical waste processing vessels - **Pulp and Paper Industry:** - Digester vessels and components - Bleach plant equipment - Chemical recovery systems - Black liquor evaporators - **Industrial Applications:** - Heat exchangers in corrosive service - Pumps and valves for aggressive chemicals - Mixing vessels for acidic solutions - Transfer lines for corrosive media --- #### **6. International Standards** The material conforms to various international specifications: | Standard | Specification | |----------|---------------| | **ASTM** | ASTM B581 - Nickel-Chromium-Iron-Molybdenum-Copper Alloy Rod
ASTM B582 - Nickel-Chromium-Iron-Molybdenum-Copper Alloy Plate, Sheet, and Strip
ASTM B619 - Welded Nickel Alloy Pipe | | **UNS** | UNS N06985 | | **ASME** | SB-581, SB-582, SB-619 | | **DIN** | DIN 17744 - NiCr21Fe18Mo | | **EN** | EN 10095 - NW 6022 | | **ISO** | ISO 6208 - NiCr21Fe18Mo | --- #### **7. Corrosion Resistance** - **Excellent** resistance to sulfuric acid across wide concentration ranges - **Outstanding** performance in phosphoric acid environments - **Superior** resistance to pitting and crevice corrosion - **Good** resistance to chloride stress corrosion cracking - **Excellent** performance in sour gas (H₂S) environments - **Good** resistance to nitric acid and other oxidizing media --- #### **8. Fabrication Characteristics** - **Machining:** Similar to stainless steel with proper tool geometry - **Welding:** Excellent weldability using GTAW, GMAW, and SMAW - **Forming:** Good hot and cold working characteristics - **Heat Treatment:** Solution anneal at 1150-1200°C (2100-2190°F) - **Annealing:** Rapid cooling from solution annealing temperature --- #### **9. Special Considerations** - **Sensitization Resistance:** Low carbon content minimizes sensitization risk - **Weld Performance:** Maintains corrosion resistance in weld zones - **Temperature Limits:** Suitable for service up to 400°C (750°F) - **Environmental Versatility:** Performs well in both oxidizing and reducing conditions --- #### **10. Summary** **Alloy G-3 (INCO G-3 / UNS N06985)** represents an advanced nickel-chromium-iron-molybdenum alloy engineered for severe corrosive environments, particularly those containing sulfuric and phosphoric acids. Its optimized composition provides enhanced corrosion resistance compared to earlier G-type alloys while maintaining excellent mechanical properties and fabricability. The alloy's balanced combination of chromium, molybdenum, and copper delivers superior performance across a broad spectrum of corrosive conditions. Governed by comprehensive international standards including ASTM B581-582, Alloy G-3 remains a preferred material for critical components in chemical processing, petrochemical, pollution control, and other industries where reliable performance in aggressive environments is essential.

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 1716 gallon liquid totes Special package is available on request.