AL 22™ Nickel-Base Alloy, UNS N06022,Specs: ASTM B-575; ASME SB-575,AL 22 alloy，1

### **Product Datasheet: AL-22™ / HASTELLOY® C-22® (UNS N06022)** **A Versatile Nickel-Chromium-Molybdenum-Tungsten Alloy for Extreme Corrosion Resistance** --- #### **1. Overview** **AL-22™**, more commonly known by its trade name **HASTELLOY® C-22®**, is a versatile nickel-chromium-molybdenum-tungsten alloy designed to withstand the most severe corrosive environments. It offers outstanding resistance to both oxidizing and reducing media, including those containing chlorides and other halogens. The alloy's optimized chemical composition provides superior resistance to **localized corrosion** (pitting and crevice corrosion) and **stress corrosion cracking (SCC)**. It also exhibits excellent thermal stability and fabricability, making it a premier choice for critical applications across the chemical process, pollution control, and oil and gas industries. --- #### **2. Chemical Composition (Typical Weight %)** The composition is carefully balanced to handle a wide spectrum of corrosive conditions. | Element | Content (%) | Role in the Alloy | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance (~56) | Provides the fundamental corrosion-resistant austenitic matrix. | | **Chromium (Cr)** | ~20.0 - 22.5 | Confers resistance to oxidizing environments (e.g., nitric acid, oxidizing salts). | | **Molybdenum (Mo)** | ~12.5 - 14.5 | Provides resistance to reducing acids (e.g., hydrochloric, sulfuric) and localized corrosion. | | **Tungsten (W)** | ~2.5 - 3.5 | Enhances resistance to reducing acids and complements molybdenum. | | **Iron (Fe)** | ~2.0 - 6.0 | Controlled residual element. | | **Cobalt (Co)** | ≤ 2.5 | Residual element. | | **Vanadium (V)** | ≤ 0.35 | Residual element. | | **Carbon (C)** | ≤ 0.015 | Kept very low to prevent carbide precipitation and sensitization. | | **Manganese (Mn)** | ≤ 0.50 | Residual element. | | **Silicon (Si)** | ≤ 0.08 | Residual element, kept very low. | --- #### **3. Physical Properties (Typical)** | Property | Value / Condition | | :--- | :--- | | **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 - 200°C) | | **Thermal Conductivity** | ~10.5 W/m·K (at 100°C) | | **Modulus of Elasticity** | ~206 GPa (30 x 10⁶ psi) at 20°C | | **Electrical Resistivity** | ~1.24 μΩ·m | --- #### **4. Mechanical Properties (Typical for Annealed Condition)** **At Room Temperature:** * **Tensile Strength:** ≥ 690 MPa (100 ksi) * **Yield Strength (0.2% Offset):** ≥ 310 MPa (45 ksi) * **Elongation:** ≥ 45% **At Elevated Temperature:** * Maintains excellent strength and creep resistance at temperatures up to approximately 1100°C (2000°F). --- #### **5. Corrosion Resistance** Alloy C-22 is renowned for its broad-spectrum corrosion resistance: * **Localized Attack:** Exceptional resistance to pitting and crevice corrosion in chloride-containing solutions. * **Oxidizing Media:** Resists nitric acid, ferric and cupric chlorides, and other oxidizing salts. * **Reducing Media:** Handles sulfuric, hydrochloric, and other reducing acids effectively. * **Mixed Acids:** Performs well in complex, multi-acid environments and oxidizing/reducing cycles. * **Stress Corrosion Cracking (SCC):** Highly resistant to chloride-induced SCC. --- #### **6. Product Applications** Alloy C-22 is used in the most demanding industrial applications: * **Chemical Processing:** Reactors, vessels, heat exchangers, and piping systems for aggressive chemical production. * **Pollution Control:** Scrubbers, ducting, and fan components in Flue Gas Desulfurization (FGD) systems. * **Pharmaceutical Industry:** Process equipment requiring high purity and resistance to corrosive cleaning agents. * **Waste Incineration & Treatment:** Components exposed to harsh flue gases and leachates. * **Pulp & Paper Industry:** Bleach plants and chemical recovery systems. --- #### **7. International and Industry Standards** Alloy C-22 (UNS N06022) is covered by several key international standards. * **UNS:** **N06022** * **Primary Standard:** * **ASTM B-575 / ASME SB-575:** Standard Specification for Low-Carbon Nickel-Molybdenum-Chromium, Nickel-Chromium-Molybdenum, Nickel-Chromium-Molybdenum-Copper, and Nickel-Chromium-Molybdenum-Tungsten Alloy Plate, Sheet, and Strip. * **Other Relevant ASTM Standards:** * **ASTM B574:** Rod and Bar * **ASTM B575:** Plate, Sheet, and Strip * **ASTM B619:** Welded Pipe * **ASTM B622:** Seamless Pipe and Tube * **ASME:** Approved for use in ASME Boiler and Pressure Vessel Code Section VIII. * **ISO:** ISO 15156-3 (NACE MR0175) for use in sour service environments. --- **Disclaimer:** The information provided herein is for reference purposes only. Properties can vary based on product form, size, and manufacturing process. Corrosion resistance is dependent on specific environmental conditions (temperature, concentration, presence of oxidizers, etc.). For design and procurement, the official, latest issue of the relevant material specification and the manufacturer's technical data must be consulted. **HASTELLOY** and **C-22** are registered trademarks of Haynes International, Inc. "AL-22" is believed to be a related trademark.

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 3377 gallon liquid totes Special package is available on request.