Influence of alloyed Fe on corrosion of Ni-Cr alloys in molten silicates and the effects of pre-oxidation treatment

The corrosion of Ni-Cr-xFe alloys (x = 6, 16, 25 wt.%) with a pre-oxidation treatment was studied in molten silicates at 1000 °C and 1050 °C. The microstructure of oxide scales following pre-oxidation treatment changes with an increase in Fe content. This content affects the mode of failure of the oxide scales at the beginning of corrosion. A failure mechanism of oxide scales is proposed, based on the microstructure evolution during corrosion. In addition, the temperature increase from 1000 °C to 1050 °C leads to an accelerated dissolution of the oxide scales without affecting the corrosion mode itself.