The Investigation of Corrosion Behaviors of Type 316L Stainless Steel in Stagnating Liquid Lithium

The corrosion behavior of Type 316L stainless steel in stagnating liquid Li under an elevated-temperature environment was investigated using a scanning electron microscope and an energy dispersive X-ray detector and self-designed laser-induced breakdown spectroscopy. A nonuniform and cell-like branched structure separated by distinct boundaries was observed, and a porous and rugged corroded layer was formed on the surface of the substrate after 500 h exposing 350°C liquid Li. This showed that the intensity of the Cr element on the superficial corroded sample decreased significantly when the depth reached ~2.8 μm and then was gradually restored in the range of ~5.6 μm. Meanwhile, the intensity of the Li element revealed consistent reduction to zero at ~4.0 μm. This study disclosed element transfer and penetration along a depth in the corrosion process between the liquid lithium and steel matrix.