Recrystallisation behaviour and mechanical properties of a novel Re-containing nickel-base superalloy

ABSTRACT

A newly developed heavily alloyed polycrystalline nickel-base superalloy containing rhenium and intended as a structural material for turbine discs in gas turbine engines has been studied. Homogenisation and heterogenisation heat treatments were developed for the as-cast superalloy, which led to improving the hot workability as compared to that of as-cast material. electron backscatter diffraction analysis of samples isothermally compressed at temperatures near the solvus temperature showed that continuous dynamic recrystallisation occurred in the superalloy leading to the formation of refined recrystallised structure. These results were used for the development of canned forging processing under quasi-isothermal conditions. The superalloy subjected to canned forging followed by aging exhibited superior high strength and high-temperature capability, while retaining reasonable ductility as compared to known disc superalloys.

KEYWORDS:

• Nickel-base superalloy
• heat treatment
• forging
• recrystallisation
• microstructure
• mechanical properties

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The present work was supported by the Russian Science Foundation [grant number 18-19-00594] and the State Assignment of the Institute for Metals Superplasticity Problems of the Russian Academy of Sciences [grant number AAAA-A17-117041310215-4]. The work was performed using the facilities of the shared services center ‘Structural and Physical-Mechanical Studies of Materials’ at the Institute for Metals Superplasticity Problems of Russian Academy of Sciences.