Precipitation Behaviour of a Complex Steel

Abstract Nanometer‐sized precipitates in tool steels are the most important microstructural constituents determining the mechanical and thermophysical properties. For the improvement of existing steel grades and the development of new tool steels a fundamental knowledge of the precipitation reactions during heat treatments and at application temperature is of vital interest. Thus, a comprehensive characterization of the various precipitates is required. This paper reviews the studies performed on a complex tool steel which hardens by secondary hardening carbides and intermetallic phases using advanced methods for characterizing nm‐sized precipitates, such as transmission electron microscopy, atom probe field ion microscopy and small‐angle neutron scattering. Additionally, computer simulations of the precipitation kinetics were performed using a novel model for nucleation, growth and coarsening of spherical precipitates in multi‐component, multi‐phase systems. It is demonstrated how experiments and simulations fit together and how thoroughly obtained experimental data help to validate and improve the theoretical models.