GOC 276 Nickel-Molybdenum-Chromium,nickel-molybdenum-chromium alloy,UNS N10276,E FORU

### **Hastelloy C-276 (UNS N10276) - Nickel-Molybdenum-Chromium Alloy** #### **Overview** Hastelloy C-276 (UNS N10276) is a **nickel-molybdenum-chromium superalloy** known as one of the most versatile **corrosion-resistant alloys** available. It is a member of the Hastelloy C-family and is classified as a "C-type" alloy. Its key characteristic is its exceptional resistance to a wide range of severe corrosive environments, including strong oxidizers and reducing acids. The alloy is designed with a low carbon content and is **solution annealed** to minimize the precipitation of carbide phases during welding, which gives it outstanding **as-welded corrosion resistance** in most applications. This combination of high nickel, molybdenum, and chromium content provides a robust defense against pitting, crevice corrosion, and stress-corrosion cracking, making it a first-choice material for the most demanding industrial applications. --- #### **Chemical Composition (Weight % - Typical)** The chemical composition of UNS N10276 is carefully balanced for maximum corrosion resistance. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | **Balance** (approx. 57%) | | **Molybdenum (Mo)** | **15.0 - 17.0** | | **Chromium (Cr)** | **14.5 - 16.5** | | **Iron (Fe)** | **4.0 - 7.0** | | **Tungsten (W)** | **3.0 - 4.5** | | **Cobalt (Co)** | **≤ 2.5** | | **Manganese (Mn)** | **≤ 1.0** | | **Vanadium (V)** | **≤ 0.35** | | **Silicon (Si)** | **≤ 0.08** | | **Carbon (C)** | **≤ 0.01** | | **Phosphorus (P)** | **≤ 0.025** | | **Sulfur (S)** | **≤ 0.01** | *The high Molybdenum content provides resistance to reducing media, while Chromium offers resistance to oxidizing conditions. The very low Carbon and Silicon content prevents carbide and silicide precipitation, ensuring stability in welded structures.* --- #### **Physical Properties** The following table outlines the key physical properties of Hastelloy C-276. | Property | Value | | :--- | :--- | | **Density** | 8.89 g/cm³ (0.321 lb/in³) | | **Melting Range** | 1325 - 1370 °C (2417 - 2498 °F) | | **Specific Heat (20°C)** | 427 J/kg·K | | **Thermal Conductivity** | 11.1 W/m·K (at 20°C) | | **Electrical Resistivity** | 1.30 μΩ·m | | **Mean Coefficient of Thermal Expansion** | 11.2 μm/m·°C (20-100°C) | | **Modulus of Elasticity (Elastic Modulus)** | 205 GPa (29.8 x 10⁶ psi) | --- #### **Mechanical Properties (Typical at Room Temperature for Annealed Condition)** Mechanical properties are typical for annealed material and can vary with product form. | Property | Typical Value | | :--- | :--- | | **Tensile Strength** | 790 MPa (115 ksi) min | | **Yield Strength (0.2% Offset)** | 355 MPa (52 ksi) min | | **Elongation (in 2 inches / 50 mm)** | 50% min | | **Hardness (Rockwell B)** | ≤ 100 HRB | --- #### **Key Characteristics & Applications** **Key Characteristics:** 1. **Exceptional Versatility:** Resists a wider range of corrosives than most other alloys. 2. **Superior Resistance to Localized Corrosion:** Excellent resistance to pitting and crevice corrosion, especially in environments containing chlorides. 3. **Oxidizing and Reducing Resistance:** Effective in both oxidizing media (due to Cr) and reducing media (due to Mo). 4. **Excellent As-Welded Performance:** The low carbon content prevents sensitization (chromium carbide precipitation) during welding, maintaining corrosion resistance in the heat-affected zone (HAZ). 5. **Resistance to Stress-Corrosion Cracking (SCC):** Highly resistant to chloride-induced SCC. **Typical Applications:** * **Chemical Processing:** Reactors, vessels, columns, and piping systems handling chlorine, acetic acid, catalysts, and other aggressive chemicals. * **Pollution Control:** Flue gas desulfurization (FGD) systems, scrubbers, ducting, and stack liners. * **Pulp and Paper Industry:** Equipment for chemical pulp processing, especially in chlorine and chlorine dioxide bleach plants. * **Waste Incineration:** Components exposed to harsh flue gases and acidic condensates. * **Pharmaceutical and Fine Chemical Industry:** Reaction vessels and transfer lines where product purity is critical. * **Marine and Offshore:** Heat exchangers and piping in seawater service. * **Acid Production and Handling:** Equipment for sulfuric, hydrochloric, and phosphoric acids. --- #### **International Standards** Hastelloy C-276 is covered by numerous international standards for various product forms. | Product Form | ASTM (USA) | ASME (USA) | EN (European) | UNS | | :--- | :--- | :--- | :--- | :--- | | **Plate, Sheet, Strip** | ASTM B575 | SB-575 | EN 2.4819 / NiMo16Cr15W | N10276 | | **Seamless Pipe & Tube** | ASTM B622 | SB-622 | EN 2.4819 / NiMo16Cr15W | N10276 | | **Welded Tube** | ASTM B619, B626 | SB-619, SB-626 | EN 2.4819 / NiMo16Cr15W | N10276 | | **Bar, Rod, Wire** | ASTM B574 | SB-574 | EN 2.4819 / NiMo16Cr15W | N10276 | | **Forgings** | ASTM B564 | SB-564 | EN 2.4819 / NiMo16Cr15W | N10276 | | **Fittings** | ASTM B366 | - | EN 2.4819 / NiMo16Cr15W | N10276 | **Note:** The primary European standard for UNS N10276 is **EN 2.4819** (Material Number: 2.4819). The common trade name "Hastelloy C-276" is a registered trademark of Haynes International. --- #### **Summary** In summary, **Hastelloy C-276 (UNS N10276)** is a premier, corrosion-resistant nickel-based alloy renowned for its versatility and reliability in the face of extremely aggressive chemical environments. Its excellent as-welded performance, resistance to localized attack, and widespread standardization make it an indispensable engineering material for critical components in chemical processing, pollution control, and other high-tech industries.

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 3195 gallon liquid totes Special package is available on request.