Mechanism of Hot Corrosion of Ni-6Al-10Cu-11Fe-15Cr Nickel Base Supperalloy in Molten Cryolite

in this paper the mechanism of hot corrosion of Ni-6Al-10Cu-11Fe-15Cr nickel base supperalloy, as a candidate for inert anodes for aluminium electrolysis, has been investigated. The samples were prepared by casting, and then were oxidized at 1000 °C for 30, 70 and 100 hours respectively. Then the surface oxide layer was studied by scanning electron microscope (SEM). Result showed that by increasing the oxidation treatment time, the thickness of oxide layers increased. The surface oxide layer was studied by XRD and it was found that the major oxide compounds that appeared on the surface were Al2O3 and Cr2O3. Also by increasing of oxidation time, the amount of mentioned compounds increased. To determine hot corrosion resistant of samples, they were exposed to molten cryolite at 930 °C for 70 hours. After hot corrosion test, the samples were examined by SEM, and dimensional variety of the samples was measured. The results showed that the sample oxidized for 100 hours, was more stable than others, and the other one oxidized for 30 hours, corroded more severely.

کلیدواژه ها:

hot corrosion ، oxidation ، inert anode ، electrolysis ، aluminium