Super elastic alloy steel wire 3J21 for spring
3J21 wire is made of 3J21 alloy, which is a cobalt - based precipitation - hardening high - elastic alloy. It is widely used in aerospace, precision instruments, medical devices and other fields due to its excellent performance.
According to ASTM F1058 standard, the chemical composition of 3J21 is as follows:
| Element | Content (%) |
| Co | 39 - 41 |
| Cr | 19 - 21 |
| Ni | 14 - 16 |
| Mo | 6.5 - 7.5 |
| Mn | 1.7 - 2.3 |
| C | 0.07 - 0.12 |
| Be | 0.01 |
| Fe | Bal. |
| Si | 0.6 |
| P | ≤0.015 |
| S | ≤0.015 |
The physical properties of 3J21 wire are shown in the following table:
| Property | Value |
| Density (g/cm³) | 8.4 |
| Resistivity (μΩ·m) | 0.92 |
| Elastic Modulus (E/MPa) | 196000 - 215500 |
| Shear Modulus (G/MPa) | 73500 - 83500 |
| Magnetic Susceptibility (K/10⁶) | 50 - 1000 |
| Melting Point (℃) | 1372 - 1405 |
- High Elasticity
- Excellent Fatigue Resistance
- Good Corrosion Resistance
- Non - magnetic
- High - temperature Resistance
- Aerospace: Used for key springs of engines, diaphragms, precision fasteners, sensor elements, etc.
- High - end Instruments and Meters: Applicable to tension wires, hairsprings, diaphragms, bellows, precision springs, etc.
- Medical Devices: Used for elastic components of surgical instruments and components of implanted devices.
- Precision Machinery and Electronics: Suitable for relay contact springs, connectors, support parts of optical devices, etc.
- Energy and Petrochemical: Used for special valve springs and elastic parts of down - hole tools.
The diameter of 3J21 wire usually ranges from 0.05mm to 6.0mm.
Different diameter specifications are suitable for making different components,
such as small - scale precision springs and sensor elements.
