UNS N07718, W.Nr. 2.4668
Inconel® 718 is a precipitation-hardenable nickel-chromium alloy that also contains significant amounts of iron, niobium and molybdenum, and minor amounts of aluminum and titanium. The alloy combines corrosion resistance and high strength with outstanding weldability, including resistance to post-weld cracking. Inconel® 718 has excellent creep rupture strength at temperatures up to 700°C. The alloy is used in gas turbines, rocket engines, spacecraft, nuclear reactors and pumps, among other applications. Recommended filler material for welding is Inconel® 718.
HARALD PIHL stocks Inconel® 718 in the following forms and standards:
Plate – AMS 5596, ASTM B670, UNS N07718
Round Bar – AMS 5662 (solution treated) and AMS 5663 (aged)
We also have the ability to produce other dimensions, forms and specifications upon request. Please contact us and we will help you find the right material for your needs.
General material description:
Type: Nickel-chromium-iron alloy, precipitation hardened with addition of niobium, molybdenum, titanium and aluminum.
Structure: Austenitic, combines solid solution and precipitation hardening.
Developed: 1960s for jet engines and gas turbines - today the standard in aviation, energy, space and offshore.
Alternative names: Inconel® 718, UNS N07718, Werkstoffnr 2.4668, ASTM B637, EN 2.4668.
Key advantages:
Very high strength from -250°C to +700°C (thanks to precipitation hardening)
Exceptional fatigue and creep resistance at high temperatures
Good corrosion resistance in many environments (incl. seawater, acids)
Excellent weldability without risk of cracking at weld joints
Stable structure even during long-term operation at high temperatures
Low susceptibility to spontaneous cracking (low susceptibility to stress corrosion cracking)
Disadvantages / limitations:
Difficult to machine in hardened condition – requires advanced machining and tools
High cost compared to simpler nickel and stainless alloys
Not optimal for environments with high concentrations of sulfuric acid or hydrochloric acid
Applications by industry and value:
Aviation industry: Jet engine components, turbine discs, exhaust parts – high strength and temperature resistance
Energy & Power: Steam and gas turbines, heat exchangers – resistance to creep and oxidation
Space industry: Rocket engines, satellite components
Offshore / Marine: Fasteners, valves, pumps – corrosion resistance and strength in marine environments
Nuclear power: Reactor components and fasteners at high temperatures
Automotive and motorsport: High-performance turbo and exhaust systems
General corrosion description:
Good corrosion resistance to many acids, seawater, saline solutions
Resistant to oxidation and pitting even at high temperatures
Low sensitivity to stress corrosion and intergranular corrosion (even after welding)
Corrosion environments where the material performs well:
Seawater, freshwater, saline solutions
Oxidizing and slightly reducing acids
High temperature environments with oxidative or sulfidizing atmospheres
Corrosive environments where the material should be avoided:
Highly concentrated hydrochloric acid (HCl)
Strongly reducing acids with high chloride or sulfur content
Hydrofluoric acid
Technical material properties:
Property (Typical value)
Yield strength (0.2%): 1035 MPa
Tensile strength: 1240 MPa
Elongation at break: 12–23%
Density: 8.19 g/cm³
Elastic modulus: 200 GPa
Thermal conductivity: ~11.4 W/m·K
Operating temperature: -250°C to +700°C (short-term up to +980°C)
Weldability: Very good
Machinability: Moderate, requires special tools
Hardness (Rockwell C): 35–45 HRC
