Graduate School

Project B6: Simulation of diffusion and microstructure evolution in the Fe-C system

Person in Charge: Dipl.-Ing. Cheng Qin

Motivation and goals:

The phase transformations and the accompanying evolution of the microstructure during the heat treatment have considerable influence on the mechanical properties of the final product of steels. The phase-field model which based on thermodynamic principals is able to provide a visualization of the development of structure and hence has acquired more attention in the research of this domain.
In Project B6 we have the following objectives of research: establish phase-field model for phase transformation in steel during the heat treatment, determine the appropriate values for the model parameter, implement and perform the simulations on computer cluster. 

Methods Results
  • Describe polycrystalline  microstructure with a multi-phase field  formulation based on the grand potential functional.
  • Application of enhanced grain boundary diffusion for simulation of  carburization
  • thermodynamic properties of the system are obtained from Calphad data
  • Comparison of the carbon diffusion simulation with the experiment result
  • Simulations for cementite nucleation and  growth at grain boundaries
  • Simulation of growth of the lamellar pearlite structure and research of relation between the growth velocity and lamellar spacing