UNS N07718

W.Nr 2.4668

Applications

Alloy 718 combines properties which make it suitable for a variety of fabricated component applications in both aircraft turbine engines and land-based turbines. These include seals, bellows, and many types of stamped metal components. The alloy is used in downhole and well head components for oil and gas wells.

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 up to 1200°F (650°C).

Industries Supplied

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

Nominal Composition

C: 0.08 max

Mn: 0.35 max

Si: 0.35 max

P: 0.015 max

S: 0.015 max

Cr: 17.0 - 21.0

Ni: 50.0 - 55.0

Mo: 2.80 - 3.30

Nb: 4.75 - 5.50

Ti: 0.65 - 1.15

Al: 0.20 - 0.80

Co: 1.0 max

Fe: Balance

Physical Properties

Density: 0.296 lb/in3, (8.19 g/cm3)

Modulus of Elasticity (E):

At 70°F (20°C): 29 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 538°C)

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

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

Applicable Specifications

Strip and Foil: AMS 5596, AMS 5597, ASTM B670

Typical Mechanical Properties

Annealed

Heat Treatment: 1800°F (980°C)

Tensile Strength: 120 - 140 ksi (830 - 965 MPa)

Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C)

Spring Temper

Tensile Strength: 180 - 230 ksi (1240 - 1585 MPa)

Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C)

After Precipitation Heat Treat

Heat Treatment: Per AMS 5596

Tensile Strength: 190 - 240 ksi (1310 - 1655 MPa)

Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C)