Inconel 718

Inconel 718 is a precipitation-hardenable nickel-chromium alloy 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 postweld cracking. The alloy has excellent creep-rupture strength at temperatures up to 700 oC (1300 oF). Used in gas turbines, rocket motors, spacecraft, nuclear reactors, pumps, and tooling.

Typical Analysis in Percentage:

              Ni(+Co):             50 - 55                         Cr:                 17 - 21

              Fe:                       bal                             Co:                     1

              Mo:                   2.8 - 3.3                        Nb(+Ta):        4.75 - 5.5

              Ti:                    0.65 - 1.15                      Al:                  0.2 -0.8

              C:                       0.08                             Mn:                  0.35

              Si:                      0.35                              B:                   0.006

              Cu:                      0.3

Physical Properties:

Density: 8.19 g/cm3 

Melting Point/Range: 1260 - 1336 oC (2300 - 2437 oF)

                                                                        J/kg ⋅ K                     Btu/lb ⋅ oF 

Specific Heat:                                              435                          0.104

                                                                       µm/m ⋅ K                   µin./in. ⋅ oF 

Avg. Coefficient of Thermal Expansion:     13.0                          7.2

                                                                         W/m ⋅ K              Btu ⋅ in./ft2 ⋅ h ⋅ oF 

Thermal Conductivity:                                 11.4                          79

Electrical Resistivity: 1250 nΩ ⋅ m 

Curie Temperature: -112 oC (-170 oF)

 

Typical Mechanical Properties:

     At Room Temperature:

         Ultimate Tensile         Yield Strength         Elongation in          Elastic Modulus

             Strength                  (0.2 % offset)          50 mm (2")              (Tension)

          MPa           ksi              MPa        ksi                  %                    GPa        106 psi

         1240           180             1036         150                 12                      211        30.6

 

Hardness: 36 HRC