Titre :

Deconstructing the Retained Austenite Stability: A Comparative Study of Two-Phase and Bulk Microstructures

Auteur(s) :

Kumpati, Joshua [Auteur]
KTH Royal Institute of Technology [Stockholm] [KTH]
Hasan, Sk. Md. [Auteur]
KTH Royal Institute of Technology [Stockholm] [KTH]
Bonvalet Rolland, Manon [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Borgenstam, Annika [Auteur]
KTH Royal Institute of Technology [Stockholm] [KTH]

Titre de la revue :

Metallurgical and Materials Transactions A

Nom court de la revue :

Metall Mater Trans A

Éditeur :

Springer Science and Business Media LLC

Date de publication :

2023-11-23

Discipline(s) HAL :

Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]

Résumé en anglais : [en]

AbstractThe stability of retained austenite is a key factor in the design of advanced high-strength steels that exhibit excellent mechanical performance, including high strength and high ductility/toughness. However, the ...
Lire la suite >AbstractThe stability of retained austenite is a key factor in the design of advanced high-strength steels that exhibit excellent mechanical performance, including high strength and high ductility/toughness. However, the contribution of certain microstructural factors, such as the morphology and size of the austenite, and the surrounding matrix, to this stability is still not fully understood, partly due to the inherent difficulties in separating these factors in multiphase microstructures. Therefore, this study uniquely compared the stabilities of retained austenite in two-phase microstructures with bulk austenitic microstructures of the same composition, across four medium-Mn steels upon quenching. By fixing the austenite chemical composition, we could exclude the influence of composition and examine the influence of other factors, such as morphology, size, and the surrounding matrix, on the stability of austenite. Our experimental results showed that retained austenite in the two-phase microstructures was more stable than the bulk austenitic microstructures of the same composition, regardless of morphology and size. Analysis using thermodynamic calculations revealed that neither the steel composition nor the size alone could explain the high stability of the retained austenite in the two-phase microstructures. Instead, we propose that microstructural factors, including size, morphology, and matrix, have a significant influence on the metastable austenite in two-phase microstructures. While these factors have been studied previously, our study introduces a novel perspective by excluding the influence of the austenite composition, thus contributing to a more comprehensive understanding of retained austenite stability. These findings may guide the design of advanced steels and highlight the importance of considering the contribution of these microstructural factors in tailoring the stability of metastable austenite.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Métallurgie Physique et Génie des Matériaux

Date de dépôt :

2023-12-12T12:52:59Z
2023-12-13T09:14:29Z
2024-01-08T14:00:42Z
2024-03-16T09:32:54Z