Maraging Steel Springs
Maraging steels are carbon free iron-nickel alloys with additions of cobalt, molybdenum, titanium and aluminium. The term maraging is derived from the strengthening mechanism, which is transforming the alloy to martensite with subsequent age hardening. Air cooling the alloy to room temperature from 820°C creates a soft iron nickel martensite, which contains molybdenum and cobalt in supersaturated solid solution. Tempering at 480 to 500°C results in strong hardening due to the precipitation of a number of intermetallic phases, including, nickel-molybdenum, iron-molybdenum and iron-nickel varieties. C300 grade has tensile strength properties up to 300 Ksi and C350 is up to 350 Ksi while still retaining excellent ductility.
Typical applications areas include :
- Aerospace, e.g. undercarriage parts and wing fittings
- tooling & machinery , e.g. extrusion press rams and mandrels in tube production, gears
- Ordnance components and fasteners.
Maraging Steel Spring Types
Maraging Steel Extension Springs Maraging Steel Wires Maraging Steel Torsion Springs Maraging Steel Compression Springs
Maraging Steel Spring Properties
| Specification | Maraging C300 | Maraging C350 |
|---|---|---|
| Nominal Composition | Nickel(Ni):18.0 - 19.0 Cobalt(Co): 8.5 - 9.5 Molybdenum(Mo): 4.6 - 5.20 Iron(Fe): Balance |
Nickel(Ni):18.0 - 19.0 Cobalt(Co): 11.5 - 12.5 Molybdenum(Mo): 4.6 - 5.20 |
| Density | 0.289 lb./in3, (8.0 g/cm3) | 0.292 lb./in3, (8.1 g/cm3) |
| Modulus of Elasticity (E) | 27.5 x 106 psi | 29 x 106 psi |
| Modulus of Rigidity (G) | 10.6 x106 psi | 11.2 x 106 psi |
| Coefficient of Expansion | 5.6 µin/in.-°F (70°F to 900°F) | 6.3 µin/in.-°F (70°F to 900°F) |
| Electrical Resistivity | 68.5 µΩ.in, (174 µΩ.cm) | 68.5 µΩ.in, (174 µΩ.cm) |
| Thermal Conductivity | 176Btu-in/ft2hr-°F, (25.3 W/m-K) | 176Btu-in/ft2hr-°F, (25.3 W/m-K) |
| Min Size | 0 | 0 |
| Max Temp | 482oC (900oF) | 482oC (900oF) |
| Uses of Maraging Steel Springs | It is resistant to crack propagation and used in aircraft or high-performance racing springs | C350 alloy is heavier and harder than C300 due to higher amounts of Cobalt. Used in high end military applications, such as, recoil springs for heavy guns. |