Corrosion of enamel with and without CaF2 in molten aluminum at 750 °C

Coatings and bulks of enamel with and without CaF2 were prepared to investigate their corrosion behavior in molten Al at 750 degrees C. Enamel coatings provide high corrosion resistance to the 304 stainless steel against molten Al. In the presence of 2.5 wt% CaF2, its corrosion resistance was further improved. Detail study on corrosion of the enamel bulks reveals that such role of CaF2 played on the corrosion behavior of enamel relies on the following two aspects: (1) Concentration of fluorides at surface reduces wettability; (2) Adding CaF2 changes crystallization of enamel, and different crystallites result in the varied corrosion resistance.