Effect of grain boundary planes on radiation-induced segregation (RIS) at near Σ3 grain boundaries in Fe-Cr alloy under ion irradiation

Abstract

Due to their good mechanical properties and corrosion resistance, Ferritic Martensitic and ODS steels are widely studied for applications in the next generation of nuclear reactor. Under irradiation, migration of point defects leads to different mechanisms including radiation-induced segregation (RIS). This type of segregation affects defect sinks such as grain boundaries (GB). Many parameters influence the amplitude of the RIS such as temperature, dose and chemical composition of the alloy. This paper presents the quantification of GB plane variation on RIS. Two different near Σ3 (60° 〈111〉) GB were investigated using EBSD and TKD for structural characterization and APT and STEM/EDXS for chemical quantification. This work revealed W-shaped profiles of Cr across GBs and a heterogeneous precipitation of Cr C rich particles in GBs planes after irradiation. Our work shows that not only the amplitude but also the sign of the Gibbsian Excess may be affected by the GB habit plane. • After irradiation segregation of Cr and C was obtained on near ∑3 in Fe-13%Cr. • Difference in orientation of habit plan has an effect on segregation profile. • Heterogeneous precipitation of Cr C rich phase was observed on the habit plan of near ∑3. • W shape profile was observed with Cr across each grain boundary after irradiation.