OSCILLATING HEAT TREATMENT METHOD FOR A SUPERALLOY

摘要

Superalloy solidified in a directional manner often cannot be subjected to heat treatment because the heat treatment leads to recrystallization. As a result of the temperature profile during a heat treatment according to the invention which oscillates in the manner of a pendulum, a recrystallization during heat treatment can be avoided because mechanical stresses are reduced thanks to the recurring succession of dissolutions and precipitations of the precipitate. The method can be applied to a Ni-based superalloy with γ-precipitates. After the cyclic heat treatment, the temperature can be adjusted to and maintained at a temperature which is the same as or higher than the complete dissolution temperature. An oscillating movement can also take place above the complete dissolution temperature.