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API6A718 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.

API6A718 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 API6A718

  • N07718
  • 2.4668
  • NC19FeNb (FR)
  • NiCr19NbMo (DE)

Nominal Composition of API6A718

Ni 53.0%, Cr 19.0%, Fe 18.5%, Nb 5.0%, Mo 3.0%

Mechanical Properties of API6A718

Ultimate Tensile Strength (N/mm²) Proof Stress (N/mm²) Elongation (%) Hardness (HB)
1034 827 17 313-354

Key Features of API6A718

  • 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 API6A718

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 API6A718

With decades of experience and a huge range of stock, Columbia Metals is an industry leader in the supply of API6A718 and other high quality specialist engineering alloys.

To buy or learn more about API6A718 contact us now, or fill in the enquiry form on the right hand side and we will be in touch shortly.

  Related Specifications Mechanical Properties
Alloy Name BS UNS BS EN Others Ultimate Tensile Strength N/mm² Minimum Yield Strength N/mm² Elongation % Hardness HB  
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