Alloy Wire International
Datasheet: Ni-Span-C Alloy 902®
Ni-Span-C Alloy 902®
A precipitation hardenable Nickel-Iron-Chromium alloy having outstanding controllable thermoelastic coefficient characteristics and excellent oxidation resistance in high temperature atmospheres. The alloy can be processed to have a constant modulus of elasticity at temperatures ranging from -45 to +65°C (-50 to +150°F).
Available in all profile options
Key Features
Outstanding controllable thermoelastic coefficient characteristics.
Can be processed to have constant modulus of elasticity from from -45 to +65ºC (-50 to +150ºF).
Good for springs in watches and weighing equipment.
Age hardenable.
Typical Applications
Springs in precise applications, such as watches and weighing machines
Designations
UNS N09902
AWS 080
Specifications
AMS 5225
AMS 5221
HS 261
Chemical Composition
| Element | Min % | Max % |
|---|---|---|
| C | – | 0.06 |
| Mn | – | 0.80 |
| Si | – | 1.00 |
| P | – | 0.04 |
| S | – | 0.04 |
| Cr | 4.90 | 5.75 |
| Ni+Co | 41.00 | 43.50 |
| Ti | 2.20 | 2.75 |
| Al | 0.30 | 0.80 |
| Cr+(Ti-4xC) | 7.10 | 8.10 |
| Co | – | 1.00 |
| Fe | Bal | Bal |
Alloy Details
| Density | Melting Point | Coefficient of Expansion | Modulus of Rigidity | Modulus of Elasticity |
|---|---|---|---|---|
| 8.05 g/cm³ | 1480 °C | 7.6 μm/m °C (20 – 100 °C) | 62 – 69 kN/mm² | 165 – 200 kN/mm² |
| 0.291 lb/in³ | 2700 °F | 4.2 x 10-6 in/in °F (70 – 212 °F) | 8993 – 10008 ksi | 23932 – 29008 ksi |
Heat treatment of finished parts
| Condition as supplied by AWI | Type | Temperature | Time | Cooling |
|---|---|---|---|---|
| Spring Temper – For good all round properties | Age Harden | 650 °C (1200 °F) | 2 Hr | Air |
| Spring Temper – For max stability | Stress Equalise Age Harden | 400 °C (750 °F) 650 °C (1200 °F) | 2 Hr 2 Hr | Air Air |
| Spring Temper – For minimum hysterisis & low thermoelastic coefficient | Stress Equalise | 400 °C (750 °F) | 2 Hr | Air |
Properties
| Annealed | ||
|---|---|---|
| Approx. tensile strength | <800 N/mm² | <116 ksi |
| Approx. operating temperature (for constant modulus applications) | -45 to +65 °C | -50 to +150 °F |
| Spring Tempered | ||
|---|---|---|
| Approx. tensile strength | 900 – 1100 N/mm² | 131 – 159 ksi |
| Approx. operating temperature (for constant modulus applications) | -45 to +65 °C | -50 to +150 °F |
| Spring Temper + Aged | ||
|---|---|---|
| Approx. tensile strength | 1300 – 1500 N/mm² | 189 – 218 ksi |
| Approx. operating temperature (for constant modulus applications) | -45 to +65 °C | -50 to +150 °F |
The above tensile strength ranges are typical. If you require different please ask.
*Trade name of Special Metals Group
