Nov 21 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesOther DesignationsFabrication and Heat Treatment Annealing Cold Working Welding Forging Aging Forming Machinability Heat TreatmentApplications
Introduction
Super alloys or high performance alloys include iron-based, cobalt-based and nickel-based alloys. These alloys can be strengthened by precipitation hardening, solid-solution hardening and work hardening methods. Super alloys can function under high mechanical stress and high temperatures and also in places that require high surface stability. Super alloys are of different shapes and have good oxidation and creep resistance.
Udimet 500™ is a nickel-chromium-cobalt alloy. The following datasheet provides an overview of Udimet 500™.
Chemical Composition
The chemical composition of Udimet 500™ is outlined in the following table.
| Element |
Content (%) |
| Nickel, Ni |
53 |
| Chromium, Cr |
17.5 |
| Cobalt, Co |
16.5 |
| Molybdenum, Mo |
4 |
| Iron, Fe |
4 |
| Titanium, Ti |
3.9 |
| Aluminum, Al |
2.9 |
| Boron, B |
0.01 |
Physical Properties
The following table shows the physical properties of Udimet 500™.
| Properties |
Metric |
Imperial |
| Density |
8.027 g/cm³ |
0.29 lb/in³ |
| Melting point |
1360°C |
2480°F |
Other Designations
Equivalent materials to Udimet 500™ are:
- AISI684
- AMS5751
- AMS5753
- ASTMB637
- DIN2.4983
Fabrication and Heat Treatment
Annealing
Udimet 500™ is annealed at 1079°C (1975°F) and then cooled in air rapidly.
Cold Working
Standard cooling methods are used for cold forming Udimet 500™. Minimization of galling is possible with the usage of heavy duty lubricants and soft die materials though the die life is limited. Tooling is recommended in the cold working process to allow liberal radii and clearances.
Welding
Welding processes recommended for Udimet 500™ include gas-tungsten arc welding, gas metal-arc welding and shielded metal-arc welding. The welding surfaces should be free from paint, crayon markings or oil.
Forging
Udimet 500™ is capable of being forged as it is ductile.
Aging
Udimet 500™ is treated at three different temperatures to be air-hardened.
- Heat for 4 h at 1079°C (1975°F) and cool in air.
- Heat for 24 h at 843°C (1550 F) and cool in air .
- Heat for 16 h at 760°C (1400°F) and cool in air.
Forming
Conventional methods can be used to form Udimet 400™ with ease as it has good ductility. Usage of heavy-duty lubricants is recommended during the cold forming process of this alloy. After the forming process all traces of the lubricant should be cleaned to prevent embrittlement of this alloy at high temperatures.
Machinability
Udimet 500™ can be machined by conventional machining methods. This alloy contains higher strength, gumminess and work-hardening qualities. Usage of water-based coolants is preferred for milling, turning or grinding. Usage of heavy lubricants is preferred for boring, drilling, broaching or tapping operations. Work-hardening of the alloy before the cutting process and chatter can be minimized by tooling and use of heavy duty machining equipment.
Heat Treatment
Udimet 500™ can be age-hardened when heat treated.
Applications
Udimet 500™ is used in gas turbine hot section components and similar industrial applications.