A systematic approach for the study of radiation-induced segregation/depletion at grain boundaries in steels

High Cr ferritic steels are candidate materials for structural applications in Gen-IV and fusion nuclear reactors. However, the relative contributions of irradiation conditions and materials microstructures on radiation-induced segregation or depletion of Cr at grain boundaries in ferritic steels are unclear. Here, the possibility of systematically analyzing the chemistry of the same grain boundary of known character during irradiation is demonstrated using a combination of electron back-scattered diffraction, atom-probe tomography and focused ion beam specimen preparation. This method provides a dynamic evolution of grain boundary chemistry as function of dose, spatial variations within the grain boundary plane, and quantification of minor solute elements such as carbon otherwise difficult to obtain experimentally.