Experimental Characterisation of the Bainitic Transformation Kinetics of Residual Austenite in Mn-Si TRIP-Assisted Multiphase Steels

P. Jacques; E. Girault; J. van Humbeeck; E. Aernoudt; F. Delannay

doi:doi:10.1051/jp4:1997573

Accès gratuit

Numéro		J. Phys. IV France Volume 07, Numéro C5, November 1997 IV^th European Symposium on Martensitic Transformations


Page(s)		C5-459 - C5-463
DOI		https://doi.org/10.1051/jp4:1997573

IV^th European Symposium on Martensitic Transformations

J. Phys. IV France 07 (1997) C5-459-C5-463
DOI: 10.1051/jp4:1997573

Experimental Characterisation of the Bainitic Transformation Kinetics of Residual Austenite in Mn-Si TRIP-Assisted Multiphase Steels

P. Jacques¹, E. Girault², J. van Humbeeck², E. Aernoudt² and F. Delannay¹

¹ Université Catholique de Louvain, Département des Sciences des Matériaux et des Procédés, PCIM Place Sainte Barbe 2, 1348 Louvain-la-Neuve, Belgium
² Department of Metallurgy and Materials Engineering, K. U. Leuven, de Croylaan 2, 3001 Leuven, Belgium

Abstract
Recent studies on TRIP-assisted multiphase steels have emphasised the drastic importance of the bainitic transformation in the optimisation of properties. Bainitic ageing is necessary for the stabilisation of austenite with respect to the martensitic transformation. This metastable retained austenite can still transform to martensite when plastically deformed (TRIP effect). The present work deals with the bainitic reaction kinetics of the austenite obtained by intercritical annealing in two low carbon Mn-Si steels. Bainitic transformation was followed by dilatometry and SEM observations. X-ray diffraction and Mössbauer spectrometry allowed the measurement of the amount of residual austenite and of the carbon enrichment in austenite. The tempering temperature was found to influence the kinetics of austenite transformation and decomposition.