Characterization and methodology for calculating the mechanical properties of a TRIP-steel submitted to hot stamping and quenching and partitioning (Q&P)

Thermomechanical simulation of quenching, hot stamping, and quenching and partitioning processes of a high-strength TRIP-assisted steel were carried out in a Gleeble (R) 3S50 thermo-mechanical simulator, coupled to the synchrotron X-ray diffraction line. The microstructures and mechanical properties were analyzed using Field Emission Gun Scanning Electron Microscopy (FEG-SEM), X-ray diffraction, and nanoindentation. The microstructures of thermomechanical treated specimens were modeled using the Object Oriented Finite Element (OOF) technique. The modeled microstructures were then fed into a finite element model to predict the mechanical behavior. By using a reverse algorithm method, the elastoplastic mechanical properties of different microconstituents were determined. This was done through the analysis of instrumented nanoindentation loading-penetration curves, Tensile properties of the thermomechanical processed steels were measured by tensile testing of subsized specimens cut from samples processed on the Gleeble (R) 3S50. The comparison between the experimental results and those of the reverse algorithm and the OOF modeled microstructure showed quite good agreement. (C) 2016 Elsevier B.V. All rights reserved.