Modelling the process chain of microalloyed case hardening steel for energy efficient high temperature carburising

Case hardening steels with selective additions of microalloying elements are used for carburizing at temperatures of 1050 degrees C and more. The addition of elements like niobium, titanium or/and aluminium together with the nitrogen content allows grain growth control in these steels. During the carburizing process the grain size of austenite depends on the particle state as well as on the kinetics of its formation from the previous structure during the heating. All previous process steps such as heat treating and plastic deformation may influence the grain stabilization effect. Phase transformation, particle formation and evolution happen during the thermal or thermo-mechanical conditioning. For a knowledge-driven design of materials and processes it is necessary to consider the entire process chain in order to reach optimal fine grain sizes in microalloyed steels. To model all the relevant steps along the process chain, various simulation programs acting on different scales have to be linked. The virtual platform concept AixViPMaP (R) is used to couple different simulation programs in order to model almost arbitrary process chains in materials processing. The data exchange is realized using a standardized, universal data format which is able to represent all factors influencing the mechanical behavior of a component in an integrative, multiscale simulation approach. Using the simulation platform, a particular process chain has been modelled and compared with experimental results.