Full-Field Microstructure Modeling During Forging a Polycrystalline γ-γ′ Nickel-Based Superalloy

The presentFull-field modeling paper demonstrates great capability of the full-field finite element DIGIMUDIGIMU®® software included recrystallizationRecrystallization models to simulate the microstructureMicrostructure evolution during forgingForging an industrial part in René 65René 65, a γ/γ′ nickel-based superalloyNickel-based superalloy. The macroscopic forgingForging conditions simulated by the finite element FORGE® software were used as the thermo-mechanical inputs of the microstructureMicrostructure simulations in the DIGIMUDIGIMU®® software. The recrystallizationRecrystallization models in the DIGIMUDIGIMU®® software were calibrated from torsion tests on laboratory-scale samples at sub-solvus and super-solvus temperatures from 1000 to 1150 °C and at strain ratesStrain rate ranging from 10–2 to 0.75 s−1. The calibrated model is able to predict, correctly, the mean and distribution of grain sizesGrain size in different deformation conditions of laboratory-scale samples and, more importantly, for eight different positions of interest in an industrial part forged by multiple operations at sub-solvus temperatures and followed by a solution heat treatmentSolution heat treatment. The differences between the predicted and experimental average grain sizesGrain size are in the range of 0.5–1.0 ASTM (which is around 1.5–3.0 µm difference when comparing to the experimental grain sizeGrain size of 10 ASTM ~11 µm). The model will help with understanding and optimizing of forgingForging processes to achieve desirable microstructuresMicrostructure and, in turn, the mechanical propertiesMechanical properties of aircraft engine forged components.