Simulation of martensitic transformations in TRIP-steel and Fe-based shape memory alloy

Several important effects in the mechanical behavior of materials are due to martensitic transformations. In case of TRIP-steels, the γ→α′ martensitic transformation during plastic deformation is responsible for high strength combined with an outstanding ductility. Another martensitic transformation (γ→ε) is the reason for the perfect shape recovery in Fe-based shape memory alloys (SMAs). By means of a finite element analysis the evolution of martensite both in a TRIP-steel and in an Fe-based SMA is investigated. The model is able to explain the experimentally observed dependence of the austenite start temperature in an Fe-based SMA on the extent of prior martensitic transformation. Dilatometric experiments with an high-alloyed TRIP-steel are used to validate the predictions of the TRIP-simulations.