Transformation induced plasticity in martensitic transformation of ferrous alloys

An experimental characterisation of transformation induced plasticity (TRIP) and related phenomena is presented for the martensitic transformation in a 16MND5 steel. Two problems are considered Assessment of the primacy of Magee or Greenwood-Johnson mechanisms : this is achieved through the evolution of TRIP in a repeated cyclic TRIP test which should be reversible for Magee mechanism and cumulative for Greenwood-Johnson mechanism. The second case is observed showing thus that Greenwood-Johnson mechanism is dominant. Coupling of an austenitic prehardening with the TRIP behavior : it is shown that this behavior is strongly influenced by a tensile or compressive prehardening and that this influence cannot be described, as sometimes mentioned, through some kind of kinematic hardening.