Electrochemical studies on high-temperature corrosion of silicon-iron coatings and iron aluminide intermetallic alloys by molten salts

摘要

The performance of Fe-Si coatings and an iron aluminide (FeAl) intermetallic alloy (FeAl 40at + 0.1 atB + 10volAl{sub}2O{sub}3) in molten salts containing vanadium pentoxide (V{sub}2O{sub}5) and sodium sulfate (Na{sub}2SO{sub}4) is reported. Corrosion and fouling by ash deposits containing V{sub}2O{sub}5 and Na{sub}2SO{sub}4 are typical corrosion problems in fuel oil fired elecfric power units. Hightemperature corrosion tests were performed using both electrochemical polanzation and immersion techniques. The temperature interval of this study was 60℃ to 900℃, and the molten salts were 80wtV{sub}2O{sub}5-20wtNa{sub}2SO{sub}4. Curves of corrosion current density vs temperature obtained by the potentiodynamic studies are reported, as well as the weight loss vs temperature curves from molten salt immersion tests. Both Fe-Si coatings and FeAl{sub}4Oat + 0.1 atB + 10volAl{sub}2O{sub}3 showed good behavior against molten salt corrosion. The final results show the potential of these coatings and alloys to solve the high-temperature corrosion in fuel oil fired electric power units.