Super Alloy INCONEL 740

Topics Covered

Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties


Inconel is a group of austenitic nickel-chromium-based super alloys designed by Special Metals Corporation. Super alloys are high performance alloys that function well in environments with very high temperature. INCONEL 740 is a nickel-chromium-cobalt alloy that is age hardenable by the precipitation of a gamma prime second phase.

The following section explains in detail about super alloy INCONEL 740.

Chemical Composition

The chemical composition of INCONEL 740 is outlined in the following table.

Element Content (%)
Nickel. Ni 48.27
Chromium, Cr 25
Cobalt, Co 20
Niobium, Nb 2
Titanium, Ti 1.8
Aluminum, Al 0.9
Iron, Fe 0.7
Silicon, Si 0.5
Molybdenum, Mo 0.5
Manganese, Mn 0.3
Carbon, C 0.03

Physical Properties

The physical properties of INCONEL 740 are tabulated below.

Properties Metric Imperial
Density 8.05 g/cm3 0.291 lb/in3
Melting point 1288 - 1362 °C 2350 - 2484 °F

Mechanical Properties

The following table shows mechanical properties of INCONEL 740.

Properties Metric Imperial
Tensile strength 1209 MPa 175300 psi
Yield strength 818.4 MPa 118700 psi
Elastic modulus 221 GPa 32 ksi
Elongation at break 36.40% 36.40%
Hardness, Rockwell C 33.6 33.6

Thermal Properties

The thermal properties of INCONEL 740 are tabulated below.

Properties Metric Imperial
Thermal expansion co-efficient (@100°C/212°F) 12.38 µm/m°C 6.878 µin/in°F
Thermal conductivity (@23°C/73.4°F) 10.2 W/m-K 70.8 BTU in/hr.ft².°F


INCONEL 740 is chiefly used in advanced power production boiler tubes and diesel engine exhaust valves.

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