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
Ni-Span-C Alloy 902® offers the following 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
Ni-Span-C Alloy 902® is known to be suitable for the following 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
The chemical composition of Ni-Span-C Alloy 902® is indicated in the table below:
| 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
Ni-Span-C Alloy 902® density, melting point, coefficient of expansion, modulus of rigidity, and elasticity is indicated in the table below:
| 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
The typical heat treatment of Ni-Span-C Alloy 902®:
| 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
The typical mechanical properties of Ni-Span-C Alloy 902®:
| 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
