摘要：This paper deals with the simulation of microstructure evolution in steels,
specifically eutectoid steels, where competitive diffusive (pearlitic) and
diffusionless (martensitic) transformations may take
place. Diffusion-controlled transformations are modelled by using the
classical Johnson-Mehl- Avrami-Kolmogorov law for isothermal transformations,
while the martensitic transformation is assumed to obey either the
Koistinen-Marburger or the Yu laws. The non-isothermal evolution of diffusive
transformations is derived from the isothermal transformation kinetics either
by invoking the additivity rule, or by integrating the rate form of the
Johnson-Mehl-Avrami-Kolmogorov law in time. The ability of both techniques to
build continuous cooling transformation (CCT) diagrams from isothermal
transformation (IT) diagrams is evaluated. Microstructure evolution is
coupled with the thermal analysis, performed using the finite element
method. A finite element analysis of a quench problem is finally carried out
to evaluate the performance of the model.
