EXTENDING THE SIZE OF ALLOY 718 ROTATING COMPONENTS

摘要

Alloy 718 rotors, in previously unheard of sizes, have been introduced into GE heavy-duty gas turbines. The forged area of each disk in a rotor is an order of magnitude larger than those of aircraft engine disks. The production challenges posed by the very large 718 ingots and forgings needed to make the rotors are discussed in this paper. The issues include segregation, abnormal grain growth and processing limitations imposed by the size of production equipment.