Corrosion behavior of 410 stainless steel in flowing lead-bismuth eutectic alloy at 550 °C

Abstract

Material compatibility and corrosion in lead-bismuth eutectic alloy (LBE) systems have been the critical issues to develop the accelerator driven systems (ADS) and the fast reactors (FR). Corrosion tests of 410 stainless steel were performed in LBE to study the corrosion behavior at 550 °C with different relative velocities. In the first part of the corrosion test, 410 stainless steel was exposed to flowing LBE with the relative velocities of 0 m/s, 1.70 m/s, 2.31 m/s, 2.98 m/s for 600 h. The second part is to immerse 410 stainless steel in the flowing LBE with the relative velocity of 2.98 m/s for 200 h, 400 h and 600 h. The results show that the oxide layer on the surface of corrosion samples is divided into an outer oxide layer, an inner oxide layer and an internal oxidation zone (IOZ). Specifically, the outer oxide layer is mainly composed of Fe3O4 and partially infiltrated Pb–Bi, the inner oxide layer is mainly made up of spinel (Fe,Cr)3O4, and the IOZ is consisting of Cr-rich oxides at the grain boundaries. Within 600 h, the corrosion degree is enhanced with the increase of corrosion time and relative velocity (0 m/s to 2.98 m/s). Moreover, the effect of prolonging corrosion time is similar to that of enhancing the flow velocity of LBE. Finally, the growth mechanism for the oxide layer of 410 stainless steel in oxygen-saturated LBE at 550 °C is proposed.