Hastelloy C-22 alloy,C-22 alloy,1

### **Introduction to Hastelloy® C-22® (UNS N06022) Nickel Alloy** **Hastelloy® C-22®** is a versatile nickel-chromium-molybdenum-tungsten alloy renowned for its exceptional, all-around corrosion resistance. It is designed to handle the most aggressive chemical environments, including strong oxidizers like chlorides, ferric salts, and nitric acid, as well as reducing acids such as sulfuric and hydrochloric. Its key advantage lies in its outstanding resistance to **localized corrosion**—pitting, crevice corrosion, and stress corrosion cracking—making it a premier choice for critical applications across the chemical processing, pollution control, and industrial sectors. --- ### **Chemical Composition (Weight %, typical)** The composition is meticulously balanced to provide optimal performance across a wide spectrum of corrosive conditions. | Element | Minimum | Maximum | Key Function | | :--- | :--- | :--- | :--- | | **Nickel (Ni)** | **Balance** | | Provides the fundamental corrosion-resistant austenitic matrix. | | **Chromium (Cr)** | 20.0 | 22.5 | Confers outstanding resistance to oxidizing media. | | **Molybdenum (Mo)** | 12.5 | 14.5 | Provides superior resistance to reducing media and pitting/crevice corrosion. | | **Tungsten (W)** | 2.5 | 3.5 | Enhances resistance to pitting and acts as a solid-solution strengthener. | | **Iron (Fe)** | 2.0 | 6.0 | Balances the composition; kept within a controlled range. | | **Cobalt (Co)** | - | 2.5 | Incidental element. | | **Vanadium (V)** | - | 0.35 | - | | **Manganese (Mn)** | - | 0.50 | - | | **Silicon (Si)** | - | 0.08 | Kept very low to prevent segregation and maintain corrosion resistance. | | **Carbon (C)** | - | 0.010 | Kept extremely low to minimize carbide precipitation during welding. | | **Sulfur (S)** | - | 0.020 | - | | **Phosphorus (P)** | - | 0.020 | - | *The balanced Cr/Mo/W ratio is the cornerstone of its versatile corrosion resistance in both oxidizing and reducing environments.* --- ### **Physical Properties (Typical)** * **Density:** 8.69 g/cm³ (0.314 lb/in³) * **Melting Range:** 1350 - 1390 °C (2460 - 2530 °F) * **Thermal Expansion Coefficient:** 12.5 μm/m·°C (20-100°C) * **Thermal Conductivity:** 10.6 W/m·K at 100°C * **Modulus of Elasticity (Young's Modulus):** 206 GPa (29.9 x 10⁶ psi) at 21°C * **Poisson's Ratio:** 0.29 --- ### **Mechanical Properties (Typical at Room Temperature, Annealed Condition)** * **Tensile Strength:** ≥ 690 MPa (100 ksi) * **Yield Strength (0.2% Offset):** ≥ 310 MPa (45 ksi) * **Elongation:** ≥ 45% --- ### **Key Characteristics and Product Applications** #### **Key Characteristics:** 1. **Versatile Corrosion Resistance:** Excellent performance in a wide range of acids, chlorides, and other aggressive chemicals, bridging the gap between purely oxidizing and purely reducing regimes. 2. **Exceptional Localized Corrosion Resistance:** Superior resistance to pitting and crevice corrosion in chloride-containing environments, even under harsh conditions (e.g., low pH, elevated temperatures). 3. **Excellent Thermal Stability:** The low carbon and silicon content provides superior resistance to sensitization and intermetallic phase formation during welding, allowing it to be used reliably in the **as-welded condition**. 4. **Good Fabricability:** It can be formed and welded using standard techniques for nickel alloys. #### **Primary Applications:** * **Chemical Processing Industry (CPI):** Reactors, vessels, heat exchangers, and piping systems handling mixed acids, chlorinated solvents, and catalyst solutions. * **Flue Gas Desulfurization (FGD) Systems:** Scrubbers, outlet ducts, stack liners, and dampers handling aggressive acidic condensates. * **Pollution Control and Waste Incineration:** Components exposed to combustion by-products and acidic scrubber streams. * **Pharmaceutical and Fine Chemical Industries:** Equipment requiring high purity and resistance to aggressive cleaning agents and process streams. * **Pulp and Paper Industry:** Bleach plants and digesters. --- ### **International Standards & Specifications** Hastelloy C-22 is comprehensively covered by a wide array of international standards, affirming its acceptance for critical service. | Product Form | Standard / Specification | Designation / Notes | | :--- | :--- | :--- | | **General Material** | **UNS** | **N06022** | | **Plate, Sheet, Strip** | ASME SB-575 / ASTM B575 | UNS N06022 | | **Bar, Billet, Forgings** | ASME SB-574 / ASTM B574 | UNS N06022 | | **Seamless Pipe & Tube** | ASME SB-622 / ASTM B622 | UNS N06022 | | **Welded Tube** | ASME SB-619 / ASTM B619, ASME SB-626 / ASTM B626 | UNS N06022 | | **Pressure Vessel Code** | **ASME Section VIII, Division 1** | Approved for use under this design code; materials must conform to the relevant ASME SB specifications above. | | **European Standards** | **DIN 17744** | **Werkstoff Nr. 2.4602** (covers all product forms) | | **TUV Certification** | **TUV Werkstoffblatt 479** | Approved for pressure equipment manufacture in the German market. | | **Welding Consumables** | AWS A5.14 / AWS A5.11 | **ERNiCrMo-10** (wire) / **ENiCrMo-10** (electrode) | **Note:** "Hastelloy" and "C-22" are registered trademarks of **Haynes International, Inc.** The ASME "SB" specifications are generally identical to the ASTM "B" specifications but carry the ASME stamp for use in ASME Code construction.

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 3267 gallon liquid totes Special package is available on request.