Critical assessment of the plasticity and fracture properties of TRIP-assisted multiphase steels

摘要

Steel research over the last decades focused on the improvement of the mechanical properties thanks to new steel grades like the TRIP-assisted multiphase steels, i.e. steels for which the strengthening mechanisms rely on the deformation-induced martensitic trans-formation (TRIP) occurring in a finely grained multi-phase microstructures. The purpose of this study is to critically assess the pros and cons of the appearance of hard and brittle martensite during straining. On the one hand, the progressive strengthening resulting from the TRIP effect is beneficial for the plastic properties. On the other hand, the fracture toughness has been evaluated. It is shown that the proportion of martensite strongly influences the damaging process and the fracture toughness of these steels.