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

Abstract

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.