K418 is a γ'phase precipitation strengthening nickel-based casting superalloy. It has good creep strength, thermal fatigue performance and oxidation resistance below 900°C. The alloy composition is relatively simple, does not contain cobalt, and has a low density. It is usually used in the as-cast state. The use of hot isostatic pressing (HIP) treatment and subsequent heat treatment can improve the plasticity and fatigue properties, and can also restore the structure and performance of parts that have degraded and reduced performance after long-term use. Long-term aging at 800°C will precipitate a small amount of σ phase, but it has no obvious effect on the performance. The alloy is suitable for manufacturing turbine rotor blades, guide blades, integral cast turbines and other high temperature parts of gas turbines operating below 900°C.

1.1 Material grade K418 (K18,518).

1.2 Similar grade INCO713C (USA).

Chemical Composition
Element                       C                Cr                  Ni               Mo               Al                Ti            Fe
Mass fraction/%   0.08-0.16   11.50-13.50    remaining    3.80-4.80    5.50-6.40    0.50-1.00     ≤1.00

Element                      Nb                B                     Zr               Mn         Si            P
Mass fraction/%  1.80-2.50    0.008-0.020     0.060-0.150    ≤0.50     ≤0.50     ≤0.015

Element                     S           Pb               Sb          As          Sn              Bi
Mass fraction/%    ≤0.010    ≤0.0005     ≤0.001    ≤0.001    ≤0.001     ≤0.00005