Alloy K500，Monel K500 ，UNS N05500，EFORU

British Specs:BS 3072 BS 3073 BS 3074 BS 3075 BS 3076 NA18，American Specs:AMS 4676 Bar and Forgings QQ-N-286，German Specs:WS 2.4375

### **Alloy K-500 / Monel K-500 / UNS N05500 - Age-Hardenable Nickel-Copper Alloy** **Introduction** Monel K-500, standardized as UNS N05500, is a precipitation-hardenable (age-hardenable) nickel-copper alloy. It possesses the excellent corrosion resistance of the base Monel 400 alloy but with the added capability of being strengthened through a thermal aging treatment. This process significantly increases its strength and hardness while maintaining good ductility. A key characteristic of Alloy K-500 is its combination of high strength and excellent corrosion resistance in a wide range of environments, including marine and chemical processing. It also exhibits low magnetic permeability and is non-magnetic to very low temperatures. **Chemical Composition (ASTM B865)** The composition is similar to Monel 400 but with the deliberate addition of Aluminum and Titanium, which form the strengthening precipitates (Ni₃(Ti,Al)) during aging. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | 63.0 min (Balance) | | **Copper (Cu)** | 27.0 - 33.0 | | **Aluminum (Al)** | 2.30 - 3.15 | | **Titanium (Ti)** | 0.35 - 0.85 | | **Iron (Fe)** | 2.0 max | | **Manganese (Mn)** | 1.5 max | | **Carbon (C)** | 0.25 max | | **Silicon (Si)** | 0.5 max | | **Sulfur (S)** | 0.01 max | *The strengthening mechanism is the precipitation of fine, coherent Ni₃(Ti,Al) gamma prime [γ'] particles within the matrix during the aging heat treatment.* **Physical Properties** | Property | Value | | :--- | :--- | | **Density** | 8.44 g/cm³ (0.305 lb/in³) | | **Melting Point** | ~ 1315-1350°C (2400-2460°F) | | **Electrical Resistivity** | ~ 65.0 μΩ·cm (Annealed) | | **Thermal Conductivity** | ~ 17.0 W/m·K (at 100°C) | | **Magnetic Response** | Essentially non-magnetic (< 1.005 μ at 200 Oe) | **Mechanical Properties (Typical for Bar & Wire - Aged Condition)** *Typical Heat Treatment: Solution Annealed + Aged at 1100°F (593°C) for 16 hours, furnace cool.* | Property | Value (Bar - Hot Finished) | Value (Wire - Cold Drawn & Aged) | | :--- | :--- | :--- | | **Tensile Strength** | 965 - 1170 MPa (140 - 170 ksi) | 1035 - 1240 MPa (150 - 180 ksi) | | **Yield Strength (0.2% Offset)** | 655 - 965 MPa (95 - 140 ksi) | 860 - 1105 MPa (125 - 160 ksi) | | **Elongation (in 2 inches / 50mm)** | 20 - 30% | 15 - 25% | | **Hardness** | 25 - 35 HRC | 28 - 38 HRC | **Key Characteristics & Advantages** 1. **High Strength & Hardness:** Offers significantly higher mechanical properties than Monel 400 due to its age-hardening capability. 2. **Excellent Corrosion Resistance:** Resists a wide variety of corrosive media, including seawater, hydrofluoric acid, sulfuric acid, alkalies, and most chlorides. It is particularly resistant to chloride-ion stress-corrosion cracking. 3. **Low Magnetic Permeability:** This property is stable down to cryogenic temperatures, making it suitable for sensitive marine and electronic applications. 4. **Good Fabricability:** Can be hot-worked, cold-worked, and machined using techniques suitable for high-strength austenitic alloys. It is readily weldable, though post-weld aging is required to restore full strength in the heat-affected zone. 5. **Maintained Ductility:** Retains good ductility and toughness even at the highest strength levels. **Product Applications** Monel K-500 is widely used in demanding marine, oil & gas, and chemical processing applications: * **Marine Engineering:** Pump shafts, propeller shafts, marine fasteners, valve components, seawater impellers, and shipboard scrapers. * **Oil & Gas:** Drill collars, downhole tool components, wellhead parts, and pump components for sour gas service. * **Chemical Processing:** Stirrers, mixer shafts, and components exposed to corrosive chemicals like hydrofluoric acid. * **Aerospace:** Monel K-500 wire is used for high-strength fasteners and springs. * **Medical:** Used in specialized surgical instruments and components requiring high strength and biocompatibility. * **Other:** Springs, scrapers, and doctor blades in the pulp and paper industry. **International Standards** Alloy K-500 / UNS N05500 is covered by numerous international standards for various product forms. | Standard Type | Standard Number | Title (or Form) | | :--- | :--- | :--- | | **UNS** | **N05500** | Unified Numbering System | | **ASTM** | B865 | Standard Specification for Precipitation Hardening Nickel-Copper-Aluminum-Titanium Alloy (UNS N05500) Bar, Rod, Wire, Plate, Sheet, and Strip | | **ASTM** | B164 | Standard Specification for Nickel-Copper Alloy Rod, Bar, and Wire (Includes K-500) | | **ASTM** | F96 | Standard Specification for Wrought Cobalt-20Nickel-20Chromium-3.5Molybdenum-3.5Tungsten-5Iron Alloy for Surgical Implant Applications (UNS R30003) (Note: K-500 is used in other medical devices) | | **AMS** | 4676 | Aerospace Material Specification - Bars, Forgings, and Rings, Corrosion and Heat-Resistant, Nickel Alloy 65Ni - 29Cu - 3Al - 1.5Ti Consumable Electrode Remelted or Vacuum Induction Melted, 1150°F (621°C) Age Hardened | | **DIN** | 2.4375 | Material designation for Nickel-Copper-Aluminum alloy (NiCu30Al) | | **EN** | NiCu30Al | European Standard designation | **Conclusion** Alloy K-500 (Monel K-500, UNS N05500) is a versatile, age-hardenable nickel-copper alloy that provides a unique combination of very high strength and outstanding corrosion resistance. Its ability to be strengthened while retaining good ductility and its non-magnetic properties make it an indispensable material for critical components in the most demanding marine, oilfield, and chemical processing 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 1702 gallon liquid totes Special package is available on request.