Electrochemical Corrosion Behavior of Hot-dip AluminizedSteel in Saline Water

摘要

Several samples of mild steel were aluminized by dipping in molten aluminium for differentdipping times. The coated samples were characterized by SEM and XRD. The potentiodynamicpolarization for the coated samples reveals that the corrosion rate is lowest at an optimumdipping time of 3 min at which the SEM showed that the coat is free of cracks. Heat treatment ofthe samples was made to re-crystallize the intermetallic layer, to reduce voids and minimize thecracks. This led to improvement in corrosion resistance of the samples. A critical dipping timeis about 3 min at which the corrosion rate is minimum. Beyond this critical time theintermetallic layer is brittle due to presence of the phase Fe2Al5 and the corrosion rate ishigher.