Grain Refinement of TRIP-Assisted Multiphase Steels through Strain-Induced Phase Transformation

摘要

To develop high performance steels for automotive applications, enhanced strengthening mechanisms are required. This study aims at assessing the critical parameters leading to the refinement of the strain-induced ferrite matrix of thermomechanically processed multiphase steels. Hot rolling simulations allowed the definition of the temperature, strain and cooling rate conditions bringing about the formation of strain-induced ferrite with a reduced grain size. The relationship between the deformation and the concurrent or subsequent phase transformations is highlighted thanks to a thorough characterisation of the generated microstructures. It is also shown that the prior austenite grain size influences the distribution of the second phases within the finely grained ferrite matrix.