Micro-Raman spectroscopic study of the corrosion of stainless steel by lead-bismuth eutectic

Lead-Bismuth Eutectic (LBE) has been proposed as a possible coolant and/or spallation target for the transmutation of nuclear waste. The corrosion of stainless steel from exposure to LBE must be understood if any transmutation scheme is to move forward. Annealed 316L, cold-rolled 316L, and D9 stainless steels corroded in a LBE environment were studied using Raman spectroscopy. Raman spectroscopy will allow identification of oxides within the corrosion layer. A micro-Raman system was constructed for these studies. The resulting Raman spectra, from annealed 316L samples show evidence for the formation of Fe3O4, instead of Fe2O3, within the corrosion layer. The main feature at 670 cm-1 matches well with the main peak of Fe3O4. Spectra from D9 samples show, in addition to a peak at 670 cm-1, a second peak at approximately 606 cm-1 that does not correlate to any oxide standards studied in this work. Raman spectra taken on iron, steel, and iron-silicon samples exposed to oxygen for short time periods also show evidence of Fe3O 4 formation.