D Cast UNS N04019 Nickel-Copper Alloy,Cast UNS N04019; 1

### **Product Introduction: D Cast UNS N04019 (M-25S) Nickel-Copper Alloy** **Overview** Cast UNS N04019, designated under the cast grade **M-25S**, is a nickel-copper alloy specifically formulated for applications requiring excellent corrosion resistance combined with enhanced wear and galling resistance. It is a variant within the MONEL® family of alloys, sharing the robust corrosion-resistant nickel-copper matrix of UNS N04400 (Monel 400), but with a significantly higher silicon content. This addition of silicon promotes the formation of hard, wear-resistant nickel-silicon phases throughout the microstructure, making M-25S an ideal choice for components subjected to abrasive, adhesive, or erosive wear in corrosive environments such as marine and chemical processing systems. --- #### **Chemical Composition (Typical % by Weight, per ASTM A494)** The composition of M-25S is balanced to provide both corrosion and wear resistance. | Element | Content (%) | Role & Benefit | | :--- | :--- | :--- | | **Nickel (Ni)** | 63.0 min (inc. Co) | Forms the primary austenitic matrix, providing the fundamental resistance to corrosion and acids. | | **Copper (Cu)** | 28.0 - 34.0 | Imparts excellent resistance to seawater, sulfuric acid, and other reducing environments. | | **Silicon (Si)** | 2.70 - 3.70 | **The key differentiating element.** Forms a hard, discontinuous nickel-silicide eutectic phase, which dramatically improves resistance to galling, abrasion, and wear. | | **Iron (Fe)** | 2.5 max | A controlled residual element. | | **Manganese (Mn)**| 1.5 max | Aids in castability and controls sulfur. | | **Carbon (C)** | 0.35 max | A residual element. | | **Sulfur (S)** | 0.025 max | A detrimental element kept to a minimum to prevent hot cracking. | *Note: "MONEL" is a registered trademark of Special Metals Corporation.* --- #### **Physical & Mechanical Properties (Typical - As-Cast or Solution Annealed)** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.44 g/cm³ (0.305 lb/in³) | | **Melting Range** | 1230 - 1315 °C (2250 - 2400 °F) | | **Tensile Strength** | 552 MPa (80 ksi) min | | **Yield Strength (0.2% Offset)** | 276 MPa (40 ksi) min | | **Elongation** | 15% min | | **Hardness** | Brinell 170 - 240 HBW (Typically harder than standard M-35-2) | --- #### **International Standards and Specifications** Cast UNS N04019 (M-25S) is specified by key industrial and military standards. * **Cast Product Standards:** * **ASTM A494 / A494M:** Standard Specification for Castings, Nickel and Nickel Alloy. (Grade M-25S) * **UNS N04019:** Unified Numbering System designation for the cast alloy. * **Military QQ-N-288 Grade D:** U.S. military specification for castings. * **Wrought Corrosion-Resistant Equivalent:** * **UNS N04400 (MONEL 400):** While not a direct wrought equivalent in terms of wear properties, it shares the same base corrosion resistance. --- #### **Product Applications** M-25S cast components are primarily used in applications where corrosion resistance must be paired with resistance to mechanical wear. 1. **Marine & Offshore:** * **Wear Rings, Bushings, and Bearings** in seawater pumps and valves. * **Seat Rings** for valves handling seawater and slurries. * **Propeller Shaft Sleeves** and other components subject to abrasive wear. 2. **Chemical Process Industry (CPI):** * **Pump Impellers and Casings** handling corrosive and abrasive slurries. * **Mixer Shafts** and **Agitator** components in reactors where particles cause erosion. * **Valve Trim** components requiring galling resistance. 3. **Oil & Gas Production:** * **Tool Joints** and **Wear Pads** for downhole tools. * Components in mud pumps and other equipment exposed to corrosive and abrasive drilling fluids. #### **Key Advantages** * **Excellent Wear Resistance:** The hard nickel-silicon eutectic phase provides superior resistance to galling, abrasion, and erosion compared to standard nickel-copper alloys. * **Good Corrosion Resistance:** Maintains excellent resistance to seawater, dilute sulfuric and hydrofluoric acids, and alkaline solutions, typical of the nickel-copper system. * **Good Mechanical Properties:** Offers a good balance of strength, hardness, and ductility for demanding service conditions. * **Proven Performance in Slurries:** Particularly effective in applications involving corrosive fluids carrying solid particles. **Conclusion** Cast UNS N04019 (M-25S) is a specialized nickel-copper casting alloy that successfully bridges the gap between corrosion resistance and wear resistance. Its high silicon content makes it uniquely suited for components that must withstand the combined assault of aggressive chemicals and mechanical abrasion, such as pump wear parts, valve seats, and marine bearings. For engineers dealing with corrosive slurries or galling issues in seawater systems, M-25S offers a robust and proven solution, fully compliant with international standards like ASTM A494 and military specification QQ-N-288.

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 3406 gallon liquid totes Special package is available on request.