The mechanical behaviour of Fe-C alloys have been determined in their
phase transformation ranges during isothermal or anisothermal transfor
mations. Two models an analytical model and a finite element model hav
e been used in order to calculate the behaviour of the material. Consi
dering a macroscopic scale, these models show that the mechanical beha
viour can be well described when an additional deformation, i.e.the tr
ansformation plasticity deformation, is considered.