Modelling and characterisation of V4C3 precipitation and cementite dissolution during tempering of Fe-C-Vmartensitic steel

The precipitation and Ostwald ripening behaviour Of V4C3 (plate shaped) particles during the tempering of a ternary Fe-C-V martensitic steel have been characterised and modelled, taking account of local equilibrium, the capillarity effect, and simultaneous cementite enrichment and dissolution. Particles Of V4C3 are represented as parabolic cylinders of revolution, with the tip radius chosen to yield the maximum lengthening rate. Transmission electron microscopy has been used to validate the theory; measurements of the average length, volume fraction, and number density of particles showed good agreement with experimental observations. (C) 2003 IoM Communications Ltd. Published by Maney for the Institute of Materials, Minerals and Mining.