The final face-to-face meeting of the PrecHiMn project served as a platform for presenting the most significant results of the project and the final conclusions
The project has been focused on the development of a detailed physical understanding of the thermodynamic and kinetic behaviour of precipitation in high manganese austenitic steels. The objective was to provide essential data for the modelling of technologically important (iron-carbide and transition-metal-carbide) precipitation processes in this new generation of high strength alloys.
The consortium that carried out the project was made up of two steel companies (ThyssenKrupp Steel Europe (TKSE), Duisburg; Arcelor Mittal Maizieres Research (AMMR), Metz), four universities (University of Oulu (UO),Oulu; Kungliga Tekniska Högskolan (KTH), Stockholm; RWTH Aachen University (RWTH), Aachen; University of Glasgow (GU), Glasgow) and one research center (CEIT-IK4 ).
Industrial partners produced laboratory casts to provide material for the project. Two base systems Fe-0.6-20Mn and Fe-0.6-30Mn were produced by TKSE and AMMR, respectively, which were systematically varied in its C, N, Al, V and Nb content. Further special castings for the themodynamic investigations were also provided.
A huge number of thermomechanical and precipitation treatments were carried out during the project by the different partners. From the thermomechanical treatments, softening kinetics and activation energies for recrystallisation were determined.
The samples produced on these treatments were analysed using advanced characterisation techniques such as FEG-SEM (EBSD) for the determination of recrystallisation state, and high resolution TEM and STEM (EELS) based techniques for precipitation state investigations.
The thermodynamic data for high manganese steels were determined based on literature data which were completed by project results. These data have been compiled in an improved thermodynamic database which is already used within the thermodynamic community.
Finally, modelling results describing the recrystallization and precipitation behaviour of microalloyed high manganese steels were reported.