Abstract
To establish a reliable lifetime prediction of hot work tool steels during service, it is necessary to characterize the initial microstructure as well as its evolution during application since the material properties depend on the microstructural configuration. The microstructure evolution during heat treatment is simulated with the software MatCalc, where the precipitation kinetics is of particular interest. The investigated X38CrMoV5-1 hot work tool steel, which has a bcc lattice structure, forms a distinct dislocation cell and subgrain structure, respectively, which is described by a dislocation density model for thermal creep using the rate theory with particular consideration of the subgrain boundary behaviour. The precipitation calculations with MatCalc are compared with microstructural investigations.