Abstract: When cast iron is added with Al, the compound layer formed by reaction between cast iron and liquid Zn at 500～600℃ consists of nubby δ +Fe-Al phases instead of column δ+г phases, and the width of the compound layer increases obviously. The consumption of Fe in cast iron is dominated by the diffusive rate of Fe through the compound layer, therefore, the corrosive rate of cast iron is decreased remarkably. With increasing the content of Al in cast iron, the corrosive rate of the cast iron further decrease. For the cast iron containing 8.1 wt.% Al, its corrosive rate is ten times as low as that of general gray cast iron.

Key words: Al cast iron, corrosion in Zn bath, Fe-Al phases