MICROSTRUCTURAL DEGRADATION OF CMSX-4: KINETICS AND EFFECT ON MECHANICAL PROPERTIES

The γ/γ’-microstructure of nickel-base superalloys gradually degrades during high temperature loading which deteriorates the mechanical properties. In the work presented the kinetics of microstructural degradation of the superalloy CMSX-4 was investigated metallographically in a wide parameter field (T, σ, t). The effect of microstructural degradation on mechanical properties was determined by mechanical testing of specimens pre-annealed under load. The laboratory results were compared with the microstructure of ex-service blades of CMSX-4.