J. Phys. IV France
Volume 112, October 2003
Page(s) 139 - 142

J. Phys. IV France
112 (2003) 139
DOI: 10.1051/jp4:2003851

The kinetics of lath martensitic transformation

G. Ghosh and G.B. Olson

Department of Materials Science and Engineering, Robert R. McCormick School of Engineering and Applied Science, Northwestem University, 2225 N. Campus Drive, Evanston, IL 60208-3108, U.S.A.

The multicomponent solution thermodynamics, a model for barrierless heterogeneous martensitic nucleation, a model for the composition and temperature dependence of the shear modulus, and a set of unique interfacial kinetic parameters are integrated to model the kinetics of lath martensitic transformation. It is shown that $M_{\rm S}$ in multicomponent alloys can be predicted within $\pm$40K. The geometrie partitioning of austenite grain and the dependence of average lath volume on the fraction transformed is established by a careful analysis of lath microstructure. The main contribution of lath martensitic transformation is due to autocatalytically generated defects.

© EDP Sciences 2003