Super Alloy Inconel 718SPF™ (UNS NO7718)

Topics Covered

Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties


Super alloys or high performance alloys have an ability to function at temperatures above 540ºC (1000ºF) with deformation resistance and high surface stability. As they have good oxidation and creep resistance, super alloys can be commonly forged, rolled to sheet or produced in various shapes. Iron-base, nickel-base and cobalt-base alloys are the major types of super alloys. Nickel-base and cobalt-base super alloys may be cast or wrought based on its composition or application. The iron-base super alloys are generally wrought alloys with stainless steel technology. These alloys can be strengthened by precipitation hardening, work hardening and solid-solution hardening.

The following section will provide details about Inconel 718SPF™, which has superelastic formability, excellent corrosion resistance and high strength.

Chemical Composition

The following table shows the chemical composition of Inconel 718SPF™.

Elements Content (%)
Nickel, Ni 50-55
Chromium, Cr 17 - 21
Iron, Fe 19
Niobium, Nb (Columbium, Cb) 4.75-5.25
Molybdenum, Mo 2.80-3.30
Cobalt, Co ≤ 1
Titanium, Ti 0.65-1.15
Silicon, Si ≤ 0.35
Manganese, Mn ≤ 0.35
Copper, Cu ≤ 0.30
Aluminum, Al 0.20-0.80
Carbon, C ≤ 0.050
Sulfur, S ≤ 0.0020
Phosphorous, P ≤ 0.015
Nitrogen, N ≤ 0.010
Boron, B ≤ 0.0060

Physical Properties

The physical properties of Inconel 718SPF™ are given in the following table.

Properties Metric Imperial
Density 8.19 g/cm³ 0.296 lb/in³

Mechanical Properties

The mechanical properties of Inconel 718SPF™ are displayed in the following table.

Properties Metric Imperial
Tensile strength 1120 MPa 162000 psi
Yield strength (at 0.2%) 827 MPa 120000 psi
Modulus of elasticity 205 GPa 29700 ksi
Poissons ratio 0.284 0.284
Elongation at break 31% 31%
Hardness, Rockwell C 24 24

Thermal Properties

The thermal properties of Inconel 718SPF™ are displayed in the following table.

Properties Metric Imperial
Thermal expansion co-efficient (at 21-93ºC/69.8-199ºF, mean; annealed and aged) 12.5 µm/m°C 6.750 µin/in°F
Thermal conductivity 11.1 W/mK 77 BTU in/hr.ft².°F

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