Contribution at the study of stress release mechanism in chromia scales formed on Ni-30Cr and Fe-47Cr : multiscale approach by Raman spectroscopy and Synchrotron microdiffraction
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access URL: https://theses.hal.science/tel-00829836
format: HTML
issued: 2026-05-10T21:18:41.793010
modified: 2026-05-10T21:18:41.760761

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Contribution at the study of stress release mechanism in chromia scales formed on Ni-30Cr and Fe-47Cr : multiscale approach by Raman spectroscopy and Synchrotron microdiffraction
type: Dataset
contact point: Organization
  fn: CCSD
keyword: fe-47cr
keyword: physcondcm-genphysics-physicscondensed-matter-cond-matother-cond-matother
keyword: theses
keyword: delamination
keyword: spectroscopie-raman
keyword: infoeu-reposemanticsdoctoralthesis
keyword: haute-temperature
keyword: microstructure
keyword: raman-spectroscopy
keyword: diffusionnal-creep
keyword: high-temperature
keyword: ni-30cr
keyword: fluage-diffusion
keyword: chromine
keyword: contraintes-residuelles
keyword: residual-stresses
keyword: scale-damage
keyword: synchrotron-microdiffraction
keyword: chromia
keyword: microdiffraction-synchrotron
keyword: endommagement
landing page: https://theses.hal.science/tel-00829836
description: Chromia-former alloy are mainly used for high temperature applications. Their ability to form a protective thermal oxide scale allows reducing oxidation kinetics of the materials. In particular, Ni-Cr and Fe-Cr alloy forms a α-Cr2O3 scale at the surface. Durability of the metal/ceramic system depends on the mechanical integrity of this scale, and also of the scale damage which could appear during oxidation or cooling. These scale damages are closely correlated to the residual stress magnitude in the oxide and to the microstructure. In this work, Ni-30Cr and Fe-47Cr alloys oxidized in air at 800, 900 and 1000°C and a multi-scale approach is proposed to a analyse with accuracy residual stress magnitude both at macroscopic scale in the adherent oxide and at local scale through delaminated area.At macroscopic scale, residual stress magnitudes are determined thanks to conventional X-Ray diffraction and Raman spectroscopy. Delamination rate in the oxide scale and diffusional creep phenomena are quantified in function of metallurgical parameters leadings to different microstructural state of the system. The influence of competition between these two stress release modes on scale damage is discussed. At microscopic scale, residual stress map through different types of delamination are performed thanks to Raman microspectroscopy and Synchrotron microdiffraction. Raman microspectroscopy is particularly appropriated to analyze delamination locally formed, due to its lateral resolution. Observations by atomic force microscopy have been performed to describe the different delamination type (dimension, height). These morphological information and associated residual stresses allows confrontation to buckling mechanic and calculation of the interface toughness. Diagrams and maps concerning the scale damages have been done thanks to these analyses.
identifier: NNT: 2012LAROS372
issued: 2026-05-10T21:18:41.784981
language: fr
modified: 2026-05-10T21:18:41.784986