Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Suzudo, Tomoaki; Nagai, Yasuyoshi*; Alfredo, C.*
no journal, ,
It is widely known that Fe-Cr binary alloys undergo spinodal decomposition when they are thermally aged, and that this microstructural evolution causes hardening and loss of ductility of the material. The present study is about the first attempt to tackle this problem by exploiting atomistic modeling techniques. We apply Monte Carlo simulation to creating spinodally-decomposed microstructure and molecular dynamics to simulating edge dislocations moving through this microstructure by imposing shearing deformation. We then measure the critical stress as a measure of hardness for many cases over the progress in spinodal decomposition, and succeed in reproducing an experimentally-discovered proportionality between the phase separation parameter and the hardening.
-ironEbihara, Kenichi; Suzudo, Tomoaki; Yamaguchi, Masatake
no journal, ,
It is desired that segregation of phosphorus(P), which is known to to cause GB embrittlement in neutron-irradiated reactor pressure vessel steels, to grain-boundary is estimated for various irradiation conditions. In order to evaluate GB P segregation using the first-principles-based rate theory model, we evaluated the diffusion coefficient(DC) for mixed interstitial dumbbell(MID) in -iron using the first-principles-based kinetic Monte Carlo(kMC) simulation, and compared it with those both for octahedral interstitial P(octP) atoms and for the vacancy(V) migration mode. As results, it was confirmed that DCs of MIDs and octP atoms are much larger than that of V migration mode. In addition, by applying the model incorporating the evaluated DCs to simulation of GB P segregation, it was found that the model needs to be modified. Furthermore, we will describe the investigation of the process of GB P segregation using molecular dynamics simulation.