Inconel® alloy 718

UNS N07718
W.Nr 2.4668

Applications

Springs, valves, and aircraft and land-based turbine engines.

Description

Inconel® 718 is an age-hardenable Nickel-Chromium-Columbium (Niobium)-Molybdenum alloy with high strength, corrosion-resistance, and good fabrication characteristics. Inconel® 718 has high tensile, yield, and creep-rupture properties at high temperatures and can operate at cryogenic temperatures up to 1200°F (650°C).

Industries Supplied

Oil & Gas Extraction, Nuclear, Aerospace, Defense and Automotive.

Nominal Composition

Ni: 50.0 - 55.0
Cr: 17.0 - 21.0
Cb (Nb): 4.75 - 5.5
Mo: 2.8 - 3.3
Ti: 0.65 - 1.15
Fe: balance
Co: 1.0 max
Al: 0.2 - 0.8
Mn: 0.35 max
Si: 0.35 max
Cu: 0.3 max

Physical Properties

Density: 0.296 lb/in3, (8.19 g/cm3)

Modulus of Elasticity (E): 
At 70°F (20°C): 29.0 x 103 ksi (200 GPa)

Modulus of Rigidity (G): 
At 70°F (20°C): 11.6 x 103 ksi (80 GPa)

Coefficient of Expansion:
7.7 µin/in.-°F (70°F to 600°F)
13.9 µm/m-°C (20°C to 300°C)

Electrical Resistivity: 47.5 µΩ.in, (121 µΩ.cm)

Thermal Conductivity: 79 Btu-in/ft2hr-°F, (11.4 W/m-K)

Applicable Specifications

Wire & Bar: AMS 5662, AMS 5663, AMS 5664, AMS 5832, AMS 5962, ASME SB-637, ASTM B637, AWS A5.14, NACE MR0175 (ISO 15156-3).

Typical Mechanical Properties – Spring Applications

  • Annealed
    • Heat Treatment: 1800°F (980°C)
    • Tensile Strength: 115 - 145 ksi; (790-1000 MPa)
    • Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C)

  • Spring Temper
    • Tensile Strength: 190 – 220 ksi; (1310 – 1515 MPa)
    • Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C​)

    • Spring Temper + Aged
    • Heat Treatment: After spring coiling. Age: 1325°F (720°C) for 8 hours, furnace cool to 1150°F and hold for a total aging time of 18 hours.
    • Tensile Strength: 220 ksi minimum; (1515 MPa)
      • Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C​)


    Inconel® is a registered trademark of the Special Metals Corporation group of companies.

    For further information Contact:

    Email: wireinfo@elgiloy.com
    Phone: 1 847 695 1900 
    Elgiloy Specialty Metals - Wire Products
    356 N.Cross Street
    Sycamore, IL 60178 USA