C70400 is a copper-nickel-silicon alloy that contains about 1.1% nickel, 1.0% silicon, and 0.5% manganese. It also includes a small amount of iron, zinc, and copper, which imparts additional properties to the material. Combining these elements gives the alloy superior mechanical and physical properties.
| Element | Content (%) |
|---|---|
| Cu | 92.4 |
| Fe | 1.5 |
| Ni | 5.5 |
| Mn | 0.6 |
C70400 has excellent mechanical properties, such as high strength, good wear resistance, and fatigue strength. According to the ASTM B171 standard, the tensile strength of UNS C70400 is around 885 MPa, and the yield strength is about 415 MPa. Additionally, it has exceptional elongation and hardness, making it ideal for high-stress applications.
C70400 has good thermal and electrical conductivity, a high melting point, and a low thermal expansion coefficient. The alloy has a density of around 8.74 g/cm³, with a specific heat capacity of 377 J/kg·K. Also, it has a thermal conductivity of 43 W/m·K and an electrical conductivity of 7.5 × 10⁷ S/m.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 8.94 g/cm3 | 0.323 lb/in³ |
| Properties | Metric | Imperial |
|---|---|---|
| Thermal expansion co-efficient (@20-300°C/68-572°F) | 17.5 µm/m°C | 9.72 µin/in°F |
| Thermal conductivity (@20°C/ 68°F ) | 64.0 W/mK | 444 BTU in/hr.ft².°F |
C70400 is widely used in marine, aerospace, and automotive industries, exhibiting excellent corrosion resistance to seawater and other harsh environments. It is also used in the chemical processing industry, exposed to acidic solutions. Additionally, it is suitable for high-pressure gas pipelines, heat exchangers, and electrical connectors.
C70400 has excellent corrosion resistance in seawater, brackish water, and other harsh environments. Its high resistance to pitting, crevice, and stress corrosion makes it an ideal material for marine applications. It also exhibits good resistance to chloride-induced stress corrosion cracking and erosion corrosion.
C70400 can be heat-treated to enhance its mechanical properties, such as strength, ductility, and toughness. Annealing, solution annealing, and stress relieving are some of the heat treatment methods used to improve the properties of UNS C70400.
C70400 has excellent machinability due to its low cutting forces, good chip formation, and low tool wear. It can be easily machined using standard processes such as drilling, turning, milling, and grinding.
UNS C70400 can be readily welded using various welding techniques, such as gas tungsten arc welding, gas metal arc welding, and resistance welding. However, it is essential to use filler metals with similar composition and properties to the base metal to avoid cracking and deformation.
