Simulations of Ion Irradiation Induced Segregation in RPV Model Alloys

Abstract

In nuclear pressure vessel steels, some alloy elements, such as Mn, Ni and Cr, can improve the mechanical and radiation resistance performances. Experiments have shown, however, that these elements will segregate and lead to clusters in the matrix after neutron/ion radiation. These segregation/clusters will reduce the toughness in the material. In this work, we simulated the radiation-induced segregation (RIS) along the ion path in bcc Fe--1.4at.%Mn--0.7at.%Ni alloys and Fe--1.7%Cr--3.3%Ni alloys currently according to RPV steel, to study the ion irradiation induced segregation of Cr/Mn and Ni, using the framework of reaction rate-theory modeling. The simulation results are compared with experiment results and demonstrated that Cr, Mn, Ni segregate along the ion irradiation path. These results are consistent with both the theoretical simulation and experimental observations.