Alloy 718 is a precipitation hardening nickel-chromium alloy that also contains additions of iron, niobium, molybdenum, aluminium and titanium, providing a unique combination of high strength and corrosion resistance together with excellent weldability.
The alloy possesses excellent tensile, fatigue, creep and rupture strengths across a wide temperature range from around -253ºC to 705ºC. The high chromium content present in the material results in excellent oxidation resistance up to temperatures of around 980ºC.
Alloy 718 also offers outstanding corrosion resistance in a variety of media. It excels in many environments including organic and inorganic acids (other than when strongly oxidising), hydrogen sulphide and sour gases. It is also especially resistant to chloride stress-corrosion cracking. This combination of properties, coupled with its exceptional weldability results in a material that truly can be described as a “Superalloy”.
Related Specifications of Alloy 718
- N07718
- AMS 5662
- AMS 5663
- AMS 5664
- ASTM B637
- 2.4668
- NC19FeNb (FR)
- NiCr19NbMo (DE)
Nominal Composition of Alloy 718
Ni 53.0%, Cr 19.0%, Fe 18.5%, Nb 5.0%, Mo 3.0%
Mechanical Properties of Alloy 718
| Ultimate Tensile Strength (N/mm²) | Proof Stress (N/mm²) | Elongation (%) | Hardness (HB) |
|---|---|---|---|
| 1034 | 827 | 17 | 313-354 |
Key Features of Alloy 718
- Excellent tensile, fatigue, creep and rupture strengths across a wide temperature range from around -253ºC to 705ºC
- Excellent oxidation resistance, up to temperatures of around 980ºC due to the high chromium content
- Outstanding corrosion resistance in many environments including organic and inorganic acids, other than when strongly oxidising, hydrogen sulphide and sour gases
- Especially resistant to chloride stress-corrosion cracking
- Exceptional weldability
Applications of Alloy 718
Offshore & marine | Fasteners, valves, choke stems, down-hole tooling, cryogenic storage tanks and pump bodies
Aerospace | Jet engine components, rocket motors and thrust reversers
Power generation | Nuclear reactor parts, gas turbine components, nuclear fuel element spacers, containment vessels and valves
Other | Hot extrusion tooling
Case Study
Alloy 718: high strength wall saw
Columbia Metals – a leading supplier of Alloy 718
With decades of experience and a huge range of stock, Columbia Metals is an industry leader in the supply of Alloy 718 and other high quality specialist engineering alloys.
To buy or learn more about Alloy 718 contact us now, or fill in the enquiry form on the right hand side and we will be in touch shortly.
