Corrosion analysis of 316L and T91 steels exposed to liquid lead-bismuth eutectic using X-ray CT

Acquiring three-dimensional (3D) corrosion data is crucial for monitoring the corrosion behaviors of stainless steels within liquid metals. In the present study, 316 L and T91 steels subjected to liquid Lead-Bismuth Eutectic (LBE) corrosion were characterized using X-ray computed tomography (CT) for the first time. CT results show that LBE residing within the grain boundaries would consistently dissolves the surrounding ferrite structure of 316 L upon extended exposure to LBE. This sustained dissolution corrosion eventually results in the formation of grain-shaped pits on the surface. Moreover, the non-uniform dissolution corrosion pattern in T91 originates from the degradation of the local oxide film caused by the continuous LBE attacks. This process eventually leads to the formation of the dissolved corrosion pits with large dimensions. Additionally, the needle-shaped 316 L and T91 samples exhibit corrosion behaviors in LBE that are consistent with those observed in bulk samples.