Udimet 718 is a fine or even ultra-fine grain nickel-chromium alloy and a member of the Inconel family of alloys. Some other names for this metal alloy are
- Allvac 718
- Haynes Alloy No. 718
- IN718
- INCONEL 718
- Inconel 718
- Pyromet Alloy 718
- UNS 07718
- UNS N07718
Although the development of the Inconel family of alloys occurred in the 1940s, Udimet 718 only dates from the early 1960s. Fabricators and manufacturers admire the metal for its many properties. Some researchers refer to this metal as a superalloy.
Qualities and Properties
This many-named alloy is high in both nickel and chromium. In addition, it also contains high amounts of iron, niobium, and molybdenum. Furthermore, it has smaller quantities of both aluminum and titanium. The combination of metals contributes to properties that include:
- Corrosion resistance (resulting from its high levels of chromium and molybdenum)
- High strength (higher than regular steel)
- High-temperature strength
- Exceptional weldability
- Resistance to post-weld cracking
- Excellent creep-rupture strength at temperatures rising to 1300°F (700°C)
The ability to withstand high temperatures arises from high levels of grain boundary precipitate hardeners. These include such metals as aluminum, niobium, tantalum and titanium.
Applications
Udimet 718 is very popular in the aerospace industry. Applications include:
- Cryogenic storage tanks
- Gas turbine hot section components
- High-speed airframe castings
- Jet engine casting
- Nuclear reactors
- Pumps
- Rocket motors
- Tooling
- Turbo pump seals
- Spacecraft
- Space shuttles
Fabricators can choose to work with Udimet in one of many forms. It is available in rounds, flats, pipes, tubes, plates, strips and more.
Choosing Udimet 718
This alloy is the metal of choice for components for aircraft engines whenever the temperature reached during its service descends 1200°F (650°C). The properties of Udimet 718 provide high-level corrosion and temperature protection. By combining this with good ductility and other qualities as well as easy machinability and welding capabilities, it is obvious why the alloy is popular in the aerospace industry.
