Jan 22 2013
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesThermal PropertiesFabrication and Heat Treatment Machinability Forming Welding Cold Working AnnealingApplications
Introduction
Super alloys have good creep and oxidation resistance, and are formed in different shapes. They have the ability to function at very high temperatures and severe mechanical stress. They are divided into three groups such as cobalt-based, nickel-based, and iron-based alloys. Solid-solution hardening, work hardening, and precipitation hardening are performed to increase their strength.
Super alloy Invar 32-5 is a modified version of Invar alloy. The following datasheet gives more details about invar 32-5.
Chemical Composition
The chemical composition of invar 32-5 is outlined in the following table.
| Elements |
Content (%) |
| Iron, Fe |
62 |
| Nickel, Ni |
32 |
| Cobalt, Co |
5.5 |
| Manganese, Mn |
0.4 |
| Silicon, Si |
0.25 |
Physical Properties
The following table shows the physical properties of Invar 32-5.
| Properties |
Metric |
Imperial |
| Density |
8.14 g/cm³ |
0.294 lb/in³ |
| Melting point |
1455°C |
2650°F |
Mechanical Properties
The mechanical properties of Invar 32-5 are given in the following table.
| Properties |
Metric |
Imperial |
| Tensile strength |
483 MPa |
70000 psi |
| Yield strength |
276 MPa |
40000 psi |
| Modulus of elasticity |
145 GPa |
21000 ksi |
| Poisson’s ratio |
0.23 |
0.23 |
| Elongation at break (in 2 in. (50.8 mm)) |
40% |
40% |
| Hardness, Rockwell B (annealed) |
75 |
75 |
| Hardness, Rockwell B (cold worked) |
90 |
90 |
| Machinability |
25 |
25 |
Thermal Properties
The thermal properties of Invar 32-5 are displayed in the following table.
| Properties |
Metric |
Imperial |
| Thermal expansion co-efficient (@ -55 - 95°C/-67to -203°F) |
0.630 µm/m°C |
0.350 µin/in°F |
Fabrication and Heat Treatment
Machinability
Super alloy Invar 32-5 can be machined using all conventional methods. Slow speeds and positive feeds are preferred for this alloy
Forming
Super alloy Invar 32-5 can be formed using all conventional methods.
Welding
Super alloy Invar 32-5 can be welded using conventional techniques.
Cold Working
Super alloy Invar 32-5 can be cold worked using conventional techniques as it has high ductility.
Annealing
Super alloy Invar 32-5 is annealed at 844°C (1550°F) followed by quenching in water.
Applications
Super alloy Invar 32-5 is used in precision measuring devices.