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E. Povoden-Karadeniz, E. Kozeschnik:
"Simulation of precipitation kinetics and precipitation strengthening of B2-precipitates in martensitic PH 13-8 Mo steel";
Talk: MS&T 2012, Pittsburgh, Pennsilvania, USA; 2012-10-07 - 2012-10-11.

In order to understand the relation between microstructure and mechanical properties of martensitic PH 13-8 Mo steel during isothermal treatment at 575 °C, the evolution of ordered bcc-B2 precipitates is predicted by precipitation kinetics simulations. In addition to the evolution of phase fractions, radii and number densities of particles, we also obtain the evolution of the nucleus chemical composition from minimization of the critical nucleation free energy. The results of the precipitation simulations are utilized for the assessment of contributions of different strengthening mechanisms to the total lower yield strength evolution. We observe good qualitative agreement between the simulated and experimental data. Anti-phase boundary as well as modulus strengthening are identified as the dominant mechanisms at the early stages of ageing at 575 °C. During the later stages beyond seven hours, precipitation strengthening is taking place under the control of the Orowan mechanism.