Dec 13 2012
Topics Covered
IntroductionPhysical PropertiesFabrication and Heat Treatment Annealing Aging Cold Working Welding Forming Machinability Heat Treatment ForgingApplications
Introduction
Super alloys also known as high performance alloys are available in three varieties that include cobalt-based, nickel-based and iron-based alloys. These alloys are of different shapes and have good oxidation and creep resistance.
Super alloys can be strengthened by precipitation hardening, solid-solution hardening and work hardening methods. They can function under high mechanical stress and high temperatures and also in places that require high surface stability.
Udimet 400™ is an age-hardenable alloy with a combination of chromium and nickel. This alloy obtains higher strength when molybdenum is added.
The following datasheet provides an overview of Udimet 400™.
Physical Properties
The following table shows the physical properties of Udimet 400™.
| Properties |
Metric |
Imperial |
| Density |
8.19 g/cm³ |
0.296lb/in³ |
| Melting point |
1371°C |
2500°F |
Fabrication and Heat Treatment
Annealing
Udimet 400™ is first cold worked and then annealed for 1h at 1038°C (1900°F) and finally cooled in a rapid manner.
Aging
Udimet 400™ is solution annealed for 4 h at 1010°C (1850°F), quenched in oil, soaked for 4 h at 843°C (1550°F), cooled in air, treated for 4 h under 760°C (1400°F) and finally cooled in air again.
Cold Working
Standard cooling methods are used for cold forming Udimet 400™. 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 during the cold working process to allow liberal radii and clearances.
Welding
Welding processes recommended for Udimet 400™ 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.
Forming
Conventional methods can be used to form Udimet 400™ with ease as it has good ductility. To obtain good forming results, powerful equipment is used along with heavy-duty lubricants. After the forming process all traces of the lubricant should be cleaned to prevent embrittlement of this alloy at high temperatures.
Machinability
Udimet 400™ can be machined by conventional machining methods and 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 400™ can be annealed and quenched in water or annealed and aged to obtain higher strength.
Forging
Udimet 400™ is capable of being forged as it is ductile.
Applications
Udimet 400™ can be used in furnaces due to its good strength at high temperature levels or in gas turbine hot section components.