Place: 2015 Bilateral Symposium of the Sino-German Cooperation Group Microstructure in Al Alloys & 1st Sino-German Symposium on Phase-Field Method and its Applications, Changsha, China
Tempering of martensitic steels to increase overall properties like ductility is a common process in materials engineering. This results in a decrease of supersaturation of alloying elements, relaxation of stresses, and precipitation of stoichiometric carbon-rich phases. This talk focuses on the modelling of the growth of precipitates and the microstructure evolution at elevated temperatures.
The simulations are done, using a multi-component multi-phase field model with finite interface dissipation  and include the steel phases austenite, ferrite, martensite, M3C, M7C3 and M23C6 with the constituents iron, carbon, chromium and manganese. Driving forces for phase transformation and diffusion are calculated with data taken from thermodynamic databases .
The martensitic geometry is calculated with the means of the phase-field method too. Complex diffusion to grain boundaries is regarded in the simulation, to insure realistic growth and precipitation behaviour.
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