INCONEL Alloy 783: An Oxidation Resistant, Low Expansion Superalloy for Gas and Steam Turbine Applications

Recently developed alloy 783 (nominal composition of Ni-34Co-26Fe-5.4Al-3Nb-3Cr, UNS R30783) is precipitation strengthened by Ni3Al-type gamma prime and NiAl-type beta phases. The alloy is being used for seals/casings in aircraft gas turbines and for bolting in steam turbines due to its low co-efficient of thermal expansion, high strength, and good oxidation resistance. It has also been specified for other aircraft gas turbine components such as rings for casings and shrouds. This paper presents the alloy’s basic characteristics, applications, and hot and cold workability.