Molten salt corrosion resistance of FeAl alloy with additions of Li, Ce and Ni

The corrosion performance of FeAl intermetallic alloys with additions of (1 at.%)Li, Ce, Ni and combinations (Ce + Li and Ce + Ni) in molten salts have been studied using the weight loss technique. Salts included Na2SO4 and NaVO3 and testing temperatures included 600, 650 and 700 °C for NaVO3, and 900, 950 and 1000 °C for Na2SO4 during 100 h. The corroded specimens were studied in the scanning electronic microscope (SEM) and the corrosion products analyzed with an X-ray energy dispersive analyzer (EDX) attached to it. The corrosion resistance in NaVO3 increases as the temperature increased, whereas in Na2SO4 decreased. The effect of the different alloying elements depended upon the salt used. In NaVO3, for instance, the FeAl + Ce + Li alloy was one with the highest corrosion rates but in Na2SO4 it had the lowest corrosion rate. The addition of these elements most of times increased the corrosion rate of the FeAl-base alloy, whereas in Na2SO4 most of times decreased the corrosion rate. The results are discussed in terms of the degree of protectiveness that the external Al2O3 layer gives to the alloys depending on the testing temperature.