Distribution of carbon in martensite during quenching and tempering of dual phase steels and consequences for damage properties - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue ISIJ international Année : 2013

Distribution of carbon in martensite during quenching and tempering of dual phase steels and consequences for damage properties

Résumé

The microstructural evolution of martensite in as-quenched and quenched and tempered Fe-0.15C-0.215Si-1.9Mn-0.195Cr wt.% dual phase (DP) steels processed to give four different errite/martensite ratios was studied. It was found that partial thermodynamic equilibrium was obtained after intercritical annealing for 130 s. The local carbon distribution in as-quenched martensite was heterogeneous for all quenching temperatures. Significant carbon enrichment was observed at the ferrite/martensite interface at annealing temperatures of 790°C, whereas carbon depletion occurred when the annealing temperature was reduced to 755°C. A possible explanation for the carbon profile in terms of the effect of Mn partitioning on the austenite phase transformation kinetics is given. The kinetics of carbide formation during tempering is strongly influenced by these carbon gradients. A simple analysis shows that the interface carbon depletion observed at lower intercritical annealing temperatures could induce a beneficial increase in the void nucleation strain ! n, due to a reduction in the backstress at the ferrite/martensite interface which decreases the local stress triaxiality. We estimate that the upper limit for the improvement in the asquenched microstructure is ~8%, so the effect could provide a moderate delay in the onset of damage. Further, we propose that the improvement in damage resistance during tempering is mainly due to dispersed void formation at tempered carbides and that this mechanism will be compromised if those carbides are localised at ferrite/martensite interfaces. This argument mitigates for the carbon-depleted interface structure obtained at lower intercritical temperatures.

Domaines

Matériaux
Fichier principal
Vignette du fichier
2013-121.pdf (2.81 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-00845782 , version 1 (28-03-2024)

Identifiants

Citer

Irina Pushkareva, Philip Scott Colin, Mohamed Gouné, Nathalie Valle, Abdelkrim Redjaïmia, et al.. Distribution of carbon in martensite during quenching and tempering of dual phase steels and consequences for damage properties. ISIJ international, 2013, 53 (7), pp.1215-1223. ⟨10.2355/isijinternational.53.1215⟩. ⟨hal-00845782⟩
178 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More