UNS C82500 is a copper-nickel-tin alloy known for its excellent corrosion resistance, high strength, and good ductility. Due to its remarkable characteristics, it is used in various industrial applications, including marine and oil and gas industries. This blog post will discuss the composition, mechanical and physical properties, uses, corrosion resistance, heat treatment, machining, and welding methods of UNS C82500.
UNS C82500 Composition
UNS C82500 is an alloy of approximately 80% copper, 10% tin, and 10% nickel, with trace amounts of iron, manganese, and phosphorus. The addition of tin to UNS C82500 enhances its strength and resistance to marine biofouling. Meanwhile, nickel improves the alloy’s resistance to corrosion by seawater and other aggressive environments.
| Element | Content (%) |
|---|---|
| Beryllium, Be | 1.90-2.25 |
| Cobalt, Co | 0.35-0.70 |
| Iron, Fe | 0.25 |
| Silicon, Si | 0.20-0.35 |
| Nickel, Ni | 0.2 |
| Aluminum, Al | 0.15 |
| Tin, Sn | 0.1 |
| Zinc, Zn | 0.1 |
| Chromium, Cr | 0.09 |
| Lead, Pb | 0.02 |
| Copper, Cu | Remainder |
UNS C82500 Mechanical Properties
UNS C82500 has a tensile strength of 620 MPa or 90,000 psi, yield strength of 230 MPa or 33,000 psi, and an elongation of 12%.
UNS C82500 Physical Properties
Its Brinell hardness is 135, and its density is 8.86 g/cm3 at 20°C. Moreover, UNS C82500 has a thermal conductivity of 33.2 W/m*K and a specific heat capacity of 377 J/kg.
UNS C82500 Uses
UNS C82500 is widely used in seawater and marine applications, such as heat exchangers, condensers, saltwater piping systems, and desalination plants. Its superior corrosion resistance and strength make it suitable for components in oil and gas industries, such as valves, pumps, flanges, and pipelines. Additionally, UNS C82500 is used in electrical and electronic components, musical instruments, and decorative objects.
UNS C82500 Corrosion Resistance
UNS C82500 has exceptional corrosion resistance in various corrosive media, including seawater, brine, and hydrogen sulfide environments. This property is attributed to the alloy’s high copper content and the addition of nickel and tin. Moreover, UNS C82500 remains resistant to pitting and crevice corrosion, stress corrosion cracking, and erosion-corrosion.
UNS C82500 Heat Treatment
UNS C82500 can be annealed at a temperature range of 593-760°C, although it is typically annealed at 650-700°C for one hour in a protective atmosphere to restore the alloy’s ductility and machinability. Moreover, UNS C82500 can be cold-worked or hot-worked at temperatures between 760 and 954°C. However, due to its high work-hardening rate, UNS C82500 requires frequent intermediate annealing processes.
UNS C82500 Machining
UNS C82500 can be machined using standard tools and techniques for copper alloys. Nevertheless, the cutting conditions should be optimized to prevent work hardening, surface cracking, and tool wear. Lubrication and cooling are also crucial to avoid overheating and material deformation.
UNS C82500 Welding
UNS C82500 can be welded using various methods, such as gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), resistance welding, and brazing. However, due to its low thermal conductivity and high thermal expansion coefficient, UNS C82500 may experience heat distortion and residual stresses during welding. To avoid this, preheating and post-weld heat treatment may be necessary, depending on the welding method and the thickness of the material.
Conclusion
UNS C82500 is a copper-nickel-tin alloy commonly used in marine and oil and gas applications due to its remarkable properties. It is resistant to corrosion, biofouling, and erosion and has high strength, good ductility, and excellent machinability. Knowing more about the composition, mechanical and physical properties, uses, corrosion resistance, heat treatment, machining, and welding methods of UNS C82500 can help you choose the best material for your project and ensure its durability and performance.
