Internal stresses and carbon enrichment in austenite of Quenching and Partitioning steels from high energy X-ray diffraction experiments
Langue
en
Article de revue
Ce document a été publié dans
Materials Science and Engineering: A. 2018-01, vol. 710, p. 245-250
Elsevier
Résumé en anglais
Quenching and Partitioning (Q&P) process permits to produce innovative microstructures containing large fraction of carbon enriched retained austenite. The present study highlights that austenite undergoes significant ...Lire la suite >
Quenching and Partitioning (Q&P) process permits to produce innovative microstructures containing large fraction of carbon enriched retained austenite. The present study highlights that austenite undergoes significant internal stresses generated during such thermal cycle. Both mechanical and chemical contributions are likely to affect its stability at room temperature and thus the resulting mechanical properties of the steel. The experiments carried out by High Energy X-Ray Diffraction (HEXRD) show unambiguously that internal stresses in austenite originate from martensitic transformation strain and from additional hydrostatic stresses induced during both reheating to partitioning temperature and final cooling. These eigenstrains are attributed to the difference in Coefficients of Thermal Expansion (CTE) between martensite and austenite and are predicted successfully with a purely elastic mean field approach. In the present study, retained austenite is shown to be in compression at room temperature. As a consequence, this state of stress contributes to stabilize retained austenite against a possible strain induced transformation at room temperature and affects the way to determine the carbon content in austenite.< Réduire
Mots clés en anglais
Steels
Q&P
Synchrotron
Internal stresses
Austenite
Martensite
Project ANR
Partition du carbone dans les phases ferritiques nanostructurées: cinétiques et microstructures
Design des Alliages Métalliques pour Allègement des Structures - ANR-11-LABX-0008
Design des Alliages Métalliques pour Allègement des Structures - ANR-11-LABX-0008
Origine
Importé de halUnités de recherche