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

Abstract

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 Na 2SO 4 and NaVO 3 and testing temperatures included 600, 650 and 700 °C for NaVO 3, and 900, 950 and 1000 °C for Na 2SO 4 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 NaVO 3 increases as the temperature increased, whereas in Na 2SO 4 decreased. The effect of the different alloying elements depended upon the salt used. In NaVO 3, for instance, the FeAl + Ce + Li alloy was one with the highest corrosion rates but in Na 2SO 4 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 Na 2SO 4 most of times decreased the corrosion rate. The results are discussed in terms of the degree of protectiveness that the external Al 2O 3 layer gives to the alloys depending on the testing temperature.