Simulation study of steels corrosion phenomenon in liquid lead-bismuth cooled reactors using molecular dynamics methods

摘要

Corrosion phenomena of stainless steel in liquid lead-bismuth as a coolant in nuclear fast breeder reactor are a field which is intensively investigated by the researchers in the recent year. We try to study this corrosion phenomena by computer simulation using molecular dynamics methods. The initial positions of the system were taken from the crystal structure data including the cell parameters and the types of the crystal. In this simulation, interatomic potential between Fe-Fe, Pb-Pb, Bi-Bi, Ni-Ni and Cr-Cr was assumed to follow Lennard-Jones potential. The Lennard-Jones potential parameters have been derived by fitting the data available in the literature. Nickel and chromium atoms were substituted into Fe crystal with the percentage of 10% and 16% to construct systems like SS 316. Molecular dynamics simulation has been done by interfacing iron and steel with liquid lead and liquid lead-bismuth in several temperatures. The result of this simulation showed that lead atoms can diffuse into Fe-10%Ni-16%Cr about 1.18 A at 773 K while in Fe-10%Ni and Fe-16%Cr about 7.25 A and 11.08 A, respectively.