Skip to Main content Skip to Navigation
Theses

Contribution à l'étude mésoscopique de la recristallisation dynamique de l'Inconel 718, lors du forgeage à chaud. : Approches expérimentale et numérique

Abstract : Developed in the 60’s, the nickel-base superalloy, Inconel 718, is widely used for hot parts of aircraft engines. The hot forging process confers to the alloy its final microstructure and its mechanical properties. The control of the process requires a deep knowledge of the interactions between the hardening phenomena and the dynamic recrystallization for the various thermomechanical conditions which are used. The present study mainly focuses on the experimental characterization of the phenomena linked to hot forging in the super-δ-solvus domain (1050 °C), as well for a single pass process as for a multipass one. Hot compression tests are used to simulate forging. After deformation, samples are helium quenched in order to freeze the microstructure that allows understanding its evolution as a function of the thermomechanical parameters (ε, and T). Microstructure analyses have then been performed using optical and scanning microscopy, EBSD, and neutron diffraction. A specific attention is paid on the study of the -phase evolution as it has a direct influence on the mechanical properties of the alloy. Its evolution is followed along thermal and thermomechanical treatments. The measure of the static and dynamic precipitation kinetics has led to a better understanding of the -phase role during hot forging at temperatures below solvus (980 °C). A sequential coupling is developed, based on two models; the first one is a crystal plasticity model implemented in a finite element code (CPFEM), the second one being a modeling of recrystallization using a cellular automata approach. The coupling allows the evolutions of the mechanical fields and the microstructure to be simulated during hot forging. The numerical results fit correctly most of the experimental data, mechanical and structural.
Document type :
Theses
Complete list of metadatas

Cited literature [166 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01726962
Contributor : Abes Star :  Contact
Submitted on : Thursday, March 8, 2018 - 4:45:00 PM
Last modification on : Wednesday, July 8, 2020 - 11:10:21 AM
Long-term archiving on: : Saturday, June 9, 2018 - 3:31:37 PM

File

Manuscrit_-_final_-_Julien_-_D...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01726962, version 1

Collections

Citation

Julien de Jaeger. Contribution à l'étude mésoscopique de la recristallisation dynamique de l'Inconel 718, lors du forgeage à chaud. : Approches expérimentale et numérique. Autre. Ecole Centrale Paris, 2013. Français. ⟨NNT : 2013ECAP0005⟩. ⟨tel-01726962⟩

Share

Metrics

Record views

246

Files downloads

314