Oxide scale formation on 316L and FeCrAl steels exposed to oxygen controlled static LBE at temperatures up to 800 °C

The corrosion behavior of three stainless steels (316L, Alkrothal 720 and Kanthal-APM) in static LBE with oxygen concentration of 10−5 wt% at temperatures of 700 °C for 230 h and 800 °C for 360 h was studied. The steel surface morphology of the oxide scales formed was investigated by SEM, XRD and Raman spectroscopy and the cross-section by SEM and EDX. A transitional inner-layer of Fe-Cr-Al oxides was found at the substrate interface and an Al-oxide outer layer on the Fe-Cr-Al alloys. Fast growing non-protective oxide scale with underlying dissolution was observed on the 316L alloy.