CX-2MW Cast UNS N26022 Severe Corrosion and Heat Resistant Alloy, 1

### **Product Introduction: CX-2MW (Cast UNS N26022) Severe Corrosion and Heat Resistant Alloy** **Overview** CX-2MW, known by its cast designation UNS N26022, is a premier nickel-chromium-molybdenum-tungsten alloy designed for the most severe corrosive and oxidizing environments. It is the cast equivalent of the widely acclaimed wrought alloy UNS N06022 (Hastelloy® C-22). This alloy represents a significant advancement in corrosion technology, offering a superior balance of resistance to both oxidizing and reducing media. It exhibits exceptional performance against pitting, crevice corrosion, and stress corrosion cracking, making it a top-tier material choice for critical applications where equipment failure is not an option. Its optimized chemistry provides enhanced thermal stability and overall corrosion resistance compared to earlier generation Ni-Cr-Mo alloys, particularly in aggressive chemical process and waste treatment applications. --- #### **Chemical Composition (Typical % by Weight, per ASTM A494)** The carefully balanced composition of CX-2MW is the cornerstone of its unmatched performance. | Element | Content (%) | Role & Benefit | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance | Forms the austenitic matrix, providing inherent corrosion resistance and mechanical integrity. | | **Chromium (Cr)** | 20.0 - 22.5 | Imparts exceptional resistance to oxidizing media (e.g., HNO₃, FeCl₃, CuCl₂, hot contaminated acids) and provides oxidation resistance at high temperatures. | | **Molybdenum (Mo)** | 12.5 - 14.5 | Provides superior resistance to reducing acids (e.g., HCl, H₂SO₄) and is critical for resisting pitting and crevice corrosion. | | **Tungsten (W)** | 2.5 - 3.5 | Synergistically enhances the effects of Molybdenum, further improving resistance to reducing acids and localized corrosion. | | **Iron (Fe)** | 2.0 - 6.0 | Balances the structure; kept within a controlled range to optimize corrosion performance. | | **Cobalt (Co)** | 2.5 max | Typically a residual element. | | **Manganese (Mn)**| 0.50 max | Aids in castability and controls sulfur. | | **Vanadium (V)** | 0.35 max | A residual element. | | **Silicon (Si)** | 0.08 max | Kept very low to improve ductility and corrosion resistance. | | **Carbon (C)** | 0.015 max | Extremely low carbon content minimizes carbide precipitation during welding or thermal exposure, ensuring excellent intergranular corrosion resistance. | | **Phosphorus (P)**| 0.02 max | Kept low to ensure good ductility and toughness. | | **Sulfur (S)** | 0.02 max | A detrimental element kept to an absolute minimum to prevent hot cracking and maintain ductility. | *Note: "Hastelloy®" is a registered trademark of Haynes International Inc.* --- #### **Physical & Mechanical Properties (Typical)** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.69 g/cm³ (0.314 lb/in³) | | **Melting Range** | 1355 - 1390 °C (2471 - 2534 °F) | | **Specific Heat** | 422 J/kg·K (0.101 BTU/lb·°F) @ 20°C | | **Thermal Conductivity**| 10.5 W/m·K (73 BTU·in/hr·ft²·°F) @ 100°C | | **Thermal Expansion** | 11.5 μm/m·°C (6.4 μin/in·°F) @ 20-100°C | | **Tensile Strength** | 586 MPa (85 ksi) min | | **Yield Strength (0.2% Offset)** | 241 MPa (35 ksi) min | | **Elongation** | 4.5% min | --- #### **International Standards and Specifications** CX-2MW is recognized and specified by major international standards for cast components. * **Cast Product Standards:** * **ASTM A494 / A494M:** Standard Specification for Castings, Nickel and Nickel Alloy. (Grade CX-2MW) * **UNS N26022:** Unified Numbering System designation for the cast alloy. * **Wrought Equivalent:** * **UNS N06022:** The standard wrought form of this alloy (e.g., plate, sheet, tube, bar). * **ASTM B574 / B575 / B622:** Standards for low-carbon nickel-chromium-molybdenum alloy rod, bar, plate, sheet, strip, and seamless pipe and tube. * **DIN 2.4602:** The corresponding material number in the German standard. --- #### **Product Applications** CX-2MW cast components are deployed in the most challenging environments across multiple industries. 1. **Chemical Processing Industry (CPI):** * Reactors, vessels, and columns for the production of acetic acid, vinyl acetate monomer, and other aggressive organic chemicals. * Pumps, valves, and agitators handling mixed acids, chlorinated streams, and catalysts. * Heat exchangers in highly corrosive service. 2. **Pollution Control & Flue Gas Desulfurization (FGD):** * Scrubber towers, outlet ducts, mist eliminators, and fan housings that resist the most corrosive conditions from sulfurous, chlorinated, and fluorinated gases. 3. **Pharmaceutical Industry:** * Critical process equipment requiring resistance to aggressive acids, salts, and cleaning agents while maintaining high purity. 4. **Waste Incineration and Treatment:** * Components in systems that process mixed chemical and municipal wastes, where chlorides and other corrosive species are present. 5. **Pulp and Paper Industry:** * Equipment in bleaching plants where oxidizing chloride environments are prevalent. #### **Key Advantages** * **Unmatched Versatility:** Offers the best overall resistance to both oxidizing and reducing environments among commercial Ni-Cr-Mo alloys. * **Superior Localized Corrosion Resistance:** Excellent resistance to pitting and crevice corrosion in chloride-containing solutions, often outperforming older alloys like C-276 and C-4. * **Excellent Thermal Stability:** The low carbon content and optimized Cr/Mo/W balance provide superior resistance to sensitization and subsequent intergranular attack during welding or thermal cycling. * **Oxidizing Acid Resistance:** The high chromium content provides exceptional resistance to oxidizing media like ferric and cupric chlorides, and nitric acid. **Conclusion** CX-2MW (UNS N26022) is a state-of-the-art corrosion-resistant casting alloy that sets the benchmark for performance in severe environments. Its superior balance of chromium, molybdenum, and tungsten delivers unparalleled resistance to a vast spectrum of corrosives. For engineers specifying materials for the most critical and aggressive applications in chemical processing, pollution control, and beyond, CX-2MW offers a reliable, high-performance solution backed by international standards like ASTM A494.

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 3394 gallon liquid totes Special package is available on request.