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J. Phys. IV France
Volume 07, Number C5, November 1997
IVth European Symposium on Martensitic Transformations
Page(s) C5-41 - C5-46
IVth European Symposium on Martensitic Transformations

J. Phys. IV France 07 (1997) C5-41-C5-46

DOI: 10.1051/jp4:1997506

Mathematical Modelling of Bainite Transformation Kinetics

N.A. Chester and H.K.D.H. Bhadeshia

University of Cambridge, Department of Materials Science and Metallurgy, Pembroke Street, Cambridge CB2 3QZ, U.K.

Steels with a mixed microstructure of allotriomorphic ferrite, bainitic ferrite, retained austenite and martensite have potentially good combinations of high strength and formability. This work describes a kinetic theory for the formation of bainite in steels where the precipitation of carbides is suppressed. The theory is based on the mechanism of transformation. It includes, for example, a nucleation model based on the Magee/Olson/Cohen theory for martensite, growth by a diffusionless mechanism in which sheaves of bainite form by the repeated nucleation of sub-units. These latter platelets grow to a size limited by plastic accommodation of the shape deformation. The theory is compared against experimental data.

© EDP Sciences 1997