Formation of Nanoscale Al 2 O 3 Protective Layer by Preheating Treatment for Improving Corrosion Resistance of Dilute Fe-Al Alloys

In this work, an attempt was made to improve the corrosion resistance of dilute Fe-Al alloys (1.0 mass% Al) by preheating treatment at 1073 K in H 2 atmosphere. In comparison with pure Fe and unpreheated Fe-Al alloys, the resistance to oxidation at 673 K in pure O 2 and to electrochemical corrosion in 5 wt.% NaCl solution is significantly improved for preheated Fe-Al alloys. This improvement is attributed to the formation of a 20 nm thin, but dense Al 2 O 3 protective layer on the surface of preheated Fe-Al alloys.