Molecular dynamic simulation on iron corrosion-reduction in high temperature molten lead-bismuth eutectic

Abstract

Molecular dynamic simulation on iron in high-temperature molten lead-bismuth eutectic has been carried out to investigate the iron corrosion and its mitigation. The aim of the work is to investigate the corrosion and evaluate proper oxygen content of injection for significant and effective reduction. To study the phenomena we calculated the diffusion coefficients, radial distribution functions and mean square displacement of iron, and also observed the microstructure of iron before and after oxygen injection into coolant. The present calculation shows that a significant and effective reduction of corrosion can be achieved by injection of 7.68×10 -2 -1.55×10 -1 wt% into coolant at temperature 750 ° C. It is predicted that the lower limit of oxygen content, 7.68×10 -2 wt%, is the minimum value to develop a self-healing stable protective oxide film for preventing high dissolution of iron; and that the upper limit of oxygen content, 1.55×10 -1 wt%, is the maximum value in order to avoid the precipitation of coolant oxides. By injection of 7.68×10 -2 wt% of oxygen, the corrosion rate has been reduced about 92.16% at 750 ° C, and reduced by 98.66% at the lower temperature 550 ° C, compared with the normal, oxygenless condition.