Effect of alloyed Al on the corrosion behaviour of Ni-base alloys in molten glass under static condition

Ni-base alloys with different Al contents of 0-10 wt.% were designed and the corrosion behaviour was evaluated by static immersion in molten glass at 1050 °C. Results indicate that a small amount of Al (2-5 wt.%) is advantageous to mitigate the corrosion of the commercial Ni-base alloy, whereas further increase of Al content (8-10 wt.%) accelerates the corrosion process. In Al-added alloys, the corrosion of Cr element is suppressed by the Al dissolution, and the formation of inner alumina in high Al alloys leads to the surface exfoliation. The corrosion mechanism strongly depends on the Al content in alloys.