Multicomponent Modeling of Radiation-Induced Segregation Behavior in Ion-irradiated Stainless Steel 316

In this work, we extended the basic ternary modeling which was reported last KNS annual meeting to the quaternary system. The RIS behavior of Si in SS 316 during the ion irradiation was calculated, and compared with the experimental results. Radiation-induced segregation (RIS) is a phenomenon of the compositional change of an alloy at sinks under irradiation at a moderated temperature. Because of its potential relevance to irradiation assisted stress corrosion cracking (IASCC) of stainless steels, a main material for reactor internals, a lot of basic research on austenitic stainless steels has been carried out in recent years. Stainless steel is basically composed of three major elements; Fe, Cr, and Ni. There are also minor elements such as Si, P and Mo. Various models have been proposed to estimate RIS in a binary and ternary model alloy containing major elements of SS. However, multicomponent modeling above quaternary system is necessary for a real system to estimate RIS of the SS