Inconel 718 is a precipitation-hardenable nickel-chromium alloy also containing significant amounts of iron, niobium, and molybdenum along with lesser amounts of aluminum and titanium. It combines corrosion resistance and high strength with outstanding weldability, including resistance to post-weld cracking. The alloy has excellent creep-rupture strength at temperatures to 1300°F (700°C). Alloy 718 is age-hardenable and can be readily fabricated, even into complex parts.
Applications of Inconel 718:
Jet engine components
Liquid-fueled rockets
Wheels, spacers, buckets, and high-temperature application bolts and fasteners
Aerospace and aircraft manufacturing
Die casting
Gas turbine engine parts
Downhole shafts
Springs
Injection molds
Cryogenic vessels
Heat exchangers
Pressure vessels
Normal product forms: ingots, billets, sheets, plates, bars, forgings, tubes, strips, and wires.
Specifications/Standard: MS 5662, AMS 5663, AMS 5664, AMS 5596, ASTM B637, and NACE MR0175.
Chemical Composition:
Nickel (Ni): 50.00-55.00%
Chromium (Cr): 17.00-21.00%
Iron (Fe): Balance
Niobium (Nb) + Tantalum (Ta): 4.75-5.50%
Molybdenum (Mo): 2.80-3.30%
Titanium (Ti): 0.65-1.15%
Aluminum (Al): 0.20-0.80%
Cobalt (Co): 1.00% max
Carbon (C): 0.08% max
Manganese (Mn): 0.35% max
Silicon (Si): 0.35% max
Physical Constants and Thermal Properties
Density: 0.296 lbs/in3, 8.19 g/cm3
Specific Gravity: 8.19
Melting Range: 2500-2600°F (1370-1430°C)
Thermal Conductivity: Varies with temperature, for example, at 21°C it is 6.5 W/m·K (11.2 Btu/(hr/ft2/in/°F))
Electrical Resistivity: Varies with temperature, for example, at 21°C it is 1.182 microhm-cm
Alloy 718 retains much of its mechanical properties up to 650°C(1200°F), although it will resist oxidation at far higher temperatures.
