Title :

Compelling Evidence for the Role of Retained Austenite in the Formation of Low Cycle Fatigue Extrusions in a 9Ni Steel

Author(s) :

Cota Araujo, Mahira-Adna [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Olive, Jean-Marc [Auteur]
Institut de Mécanique et d'Ingénierie de Bordeaux [I2M]
Pecastaings, Gilles [Auteur]
Centre de Recherche Paul Pascal [CRPP]
Addad, Ahmed [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Bouquerel, Jeremie [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Vogt, Jean-Bernard [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207

Journal title :

Metals

Abbreviated title :

Metals

Volume number :

13

Pages :

546

Publisher :

MDPI AG

Publication date :

2023-03-08

ISSN :

2075-4701

English keyword(s) :

martensite
cyclic plasticity
magnetic force microscopy
advanced electron microscopy

HAL domain(s) :

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

English abstract : [en]

The 9Ni martensitic steels have a martensitic microstructure which contains retained austenite after solution heat treatment and water quenching. Under low cycle fatigue, extrusions formed at the surface of the material ...
Show more >The 9Ni martensitic steels have a martensitic microstructure which contains retained austenite after solution heat treatment and water quenching. Under low cycle fatigue, extrusions formed at the surface of the material and were very close to martensite lath boundaries. The presence of retained austenite at martensite laths has been highly suspected to impact the cyclic plasticity. However, the nano-size of the austenitic phase makes it difficult to obtain clear evidence of its role. The paper focuses on the precise determination of these extrusions and the link with the retained austenite. The paper also emphasizes the innovative and promising use of magnetic force microscopy (MFM) to document cyclic plasticity of a 9Ni steel. It is shown that electron microscopies, even the most advanced ones, may be unsuccessful in reaching this goal, while magnetic force microscopy (MFM) overcame the difficulty. This technique has allowed imaging of both the extrusion and the retained austenite. These analyses confirm that the fatigue extrusions originated from a local displacement of martensite lath. The proposed mechanism, in which the retained austenitic film acts as a lubricant film or greasy film promoting a flowing of martensite along the interfaces, is unambiguously demonstrated.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Métallurgie Physique et Génie des Matériaux

Submission date :

2023-03-11T10:48:42Z
2023-03-13T12:41:10Z