INCONEL Alloy 686 Nickel Superalloy (UNS N06686),W.Nr. 2.4606，1

### **Product Introduction: INCONEL® Alloy 686 (UNS N06686, W.Nr. 2.4606)** **INCONEL® Alloy 686** is a nickel-chromium-molybdenum-tungsten superalloy recognized as one of the most versatile corrosion-resistant materials available. It demonstrates exceptional performance in both oxidizing and reducing environments, offering superior resistance to pitting, crevice corrosion, and stress corrosion cracking. The alloy's optimized composition provides outstanding protection in a wide range of aggressive media, including strong oxidizing acids, chlorides, and mixed acid solutions. This alloy maintains excellent fabricability and weldability characteristics while providing enhanced corrosion resistance compared to other nickel-chromium-molybdenum alloys, making it suitable for the most demanding chemical processing applications. --- ### **Chemical Composition** | Element | Content (%) | |---------|-------------| | **Nickel (Ni)** | Balance | | **Chromium (Cr)** | 19.0 - 23.0 | | **Molybdenum (Mo)** | 15.0 - 17.0 | | **Tungsten (W)** | 3.0 - 4.4 | | **Iron (Fe)** | 5.0 max | | **Manganese (Mn)** | 0.75 max | | **Vanadium (V)** | 0.035 max | | **Silicon (Si)** | 0.08 max | | **Cobalt (Co)** | 0.05 max | | **Carbon (C)** | 0.01 max | | **Phosphorus (P)** | 0.04 max | | **Sulfur (S)** | 0.02 max | --- ### **Physical Properties** | Property | Value | |----------|-------| | **Density** | 8.92 g/cm³ | | **Melting Point** | 1335-1380 °C | | **Thermal Conductivity** | 10.1 W/m·K (at 20°C) | | **Electrical Resistivity** | 1.35 μΩ·m | | **Modulus of Elasticity** | 210 GPa | | **Coefficient of Thermal Expansion** | 11.5 μm/m·°C (20-100°C) | | **Specific Heat Capacity** | 420 J/kg·K | | **Magnetic Permeability** | <1.001 | --- ### **Mechanical Properties** **Room Temperature Properties (Annealed):** - **Tensile Strength:** 758 MPa (min) - **Yield Strength (0.2% Offset):** 358 MPa (min) - **Elongation:** 55% (min) - **Hardness:** 98 HRB (max) **Elevated Temperature Performance:** - **Tensile Strength at 540°C:** 600 MPa - **Yield Strength at 540°C:** 290 MPa - **Excellent creep strength up to 425°C** - **Good thermal stability** --- ### **Key Characteristics & Advantages** 1. **Exceptional Corrosion Resistance** - Outstanding resistance to sulfuric, hydrochloric, and phosphoric acids - Superior performance in mixed acid environments - Excellent resistance to pitting and crevice corrosion (PREN > 50) 2. **Versatile Environmental Performance** - Handles both oxidizing and reducing conditions effectively - Excellent resistance to chloride-induced stress corrosion cracking - Superior performance in acidic salt solutions 3. **Enhanced Alloy Composition** - Optimized chromium content for oxidizing environments - High molybdenum and tungsten content for reducing conditions - Ultra-low carbon and silicon for improved weldability 4. **Excellent Fabricability** - Good weldability using conventional methods (GTAW, GMAW) - Suitable for hot and cold working operations - Maintains corrosion resistance in as-welded condition --- ### **Product Applications** **Chemical Processing Industry:** - Reactors and pressure vessels - Heat exchangers and condensers - Piping systems and pumps - Distillation columns and scrubbers **Pollution Control:** - Flue gas desulfurization systems - Scrubbers and absorbers - Waste water treatment equipment - Acid waste handling systems **Pharmaceutical Industry:** - Reaction vessels and reactors - Processing equipment and piping - Purification and filtration systems **Pulp and Paper Industry:** - Bleach plant equipment - Chemical recovery systems - Digester components --- ### **International Standards** | Standard Type | Standard Number | Product Form | |---------------|-----------------|--------------| | **UNS** | N06686 | Unified Numbering System | | **Werkstoff Nr.** | 2.4606 | Material Number | | **ASTM** | B575 | Plate, Sheet, and Strip | | **ASTM** | B574 | Rod and Bar | | **ASTM** | B619/B622 | Welded and Seamless Pipe | | **ASME** | SB-575, SB-574 | Code Cases | | **DIN** | 2.4606 | German Standard | | **NACE** | MR0175/ISO 15156 | Sour Service Applications | --- ### **Summary** **INCONEL® Alloy 686 (UNS N06686, W.Nr. 2.4606)** represents the pinnacle of corrosion-resistant nickel-based alloys, offering unparalleled performance in the most aggressive chemical environments. Its carefully balanced composition provides exceptional resistance to a wide spectrum of corrosive media, including strong acids, chlorides, and mixed chemical solutions. The alloy's enhanced resistance to localized corrosion, combined with excellent fabricability and weldability, makes it an ideal choice for critical components in chemical processing, pollution control, pharmaceutical, and pulp and paper industries. Certification to major international standards including ASTM, ASME, and NACE specifications ensures consistent quality and reliability, providing engineers with a superior material solution for the most demanding applications where maximum corrosion resistance and long-term performance 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 3332 gallon liquid totes Special package is available on request.