Corrosion studies of Fe3Al-Fe3AlC intermetallics in 0.25 n H2SO4 using microelectrochemical method and SAES analysis

Abstract

Aqueous corrosion behavior of the dual-phase Fe3Al-Fe3AlC iron aluminide was investigated in 0.25 N H2SO4 using a microelectrochemical technique and scanning Auger electron spectroscopy (SAES) to explore corrosion and passivation behavior of the individual phase, i.e., Fe3Al and Fe3AlC. The corrosion resistance of the matrix (Fe3Al) phase evaluated in terms of electrochemical parameters such as corrosion current density, passive current density, and critical current density were found superior to that of the carbide phase. The passive film formed on the matrix phase was more stable compared with that on the carbide phase. Low Al content and presence of C in the carbide phase were attributed to its poor passivation behavior. (c) 2007 The Electrochemical Society.