New metallurgical tools for optimum design of modern ultra high strength low carbon martensitic steels (TOOLMART) : final report

The metallurgical design of modern UHSS that satisfy customer requirements has become a challenging task for which no fully adapted and reliable tools are currently available as key aspects for the metallurgical design faces limitations: a) Prediction of martensite transformation temperatures, kinetics and critical cooling rates b) Description of microstructural evolution and quantification of microstructural changes during autotempering and low temperature tempering c) Complete and accurate characterization of martensite microstructures d) Identification and quantification of critical parameters for strength, damage, toughness and hydrogen absorption. In the frame of the RFCS project ToolMart, Arcelor Mittal, Tata Steel and Max Planck Institute have been developed a workbench for modern low carbon (below 0.25wt%) full martensitic product. This workbench provides a new approach for modern martensitic product design using advanced characterization techniques adapted to low carbon martensite such as SEM/EBSD, TEM, Atom Probe Tomography, neutron small angle scattering and synchrotron high-resolution diffraction.