Phase-field simulation on the formation of ferromagnetic phase during creep deformation in SUS304 steel

Tsukada, Yuki*; Shiraki, Atsuhiro*; Murata, Yoshinori*; Morinaga, Masahiko*; Takaya, Shigeru  ; Koyama, Toshiyuki*

The formation of the ferromagnetic phase during creep deformation in SUS304 steel was simulated by aphase-field method. In order to consider the precipitation and growth of the phase simultaneously, we haveconstructed a model based on experimental results. In this model, strain energy stored near carbideduring creep deformation increases the driving force for precipitation of the phase. This strain energy isestimated on the basis of distribution function of dislocation density in space near the carbide and is used inthe calculation of the activation energy for nucleation of the phase. Changes in mole fraction of both carbide and the phase are reproduced well in this simulation. Furthermore, it is found that theincrease rate of dislocation density during creep process affects the manner of the change in mole fraction ofthe phase.