Corrosion of metals and alloys in molten glasses. Part 1: glass electrochemical properties and pure metal (Fe, Co, Ni, Cr) behaviours

Corrosion of pure metals Fe, Ni, Co, Cr in molten glass was studied at 1050 °C by electrochemical techniques and thickness losses measurements. These two techniques are in good agreement. The electrochemical apparatus was used to determine the formal potential of some redox couples, to identify the corrosion reactions and to evaluate the corrosion rates.Among tested metals, only chromium is a passivable material. The passivation is due to the formation of a chromium oxide (Cr₂O₃) protective layer at the glass/metal interface. Then superalloys used in molten glass must contain a high chromium level to resist to corrosion.