Effect of anodizing on galvanic corrosion resistance of Al coupled to Fe or type 430 stainless steel in diluted synthetic seawater

Highlights: • The anodizing of Al was shown to prevent the galvanic corrosion of Al/Fe in diluted seawater. • The threshold film thickness required for the prevention of galvanic corrosion was derived. • The electrochemical properties of anodizing films for corrosion prevention were determined. • The anodizing conditions for the corrosion prevention of Al/Type 430ss were shown. In 100-times diluted synthetic seawater at 298 K (pH 8.2), the effect of anodizing on the galvanic corrosion resistance of Al coupled to Fe or Type 430 stainless steel was investigated by measuring the galvanic current densities and electrode potentials of the Al. The optimal anodizing conditions for the corrosion prevention of Al/Fe and Al/Type 430 were determined. The results of this study clearly indicate that the increase in the initiation potential of localized corrosion due to anodizing in H₂SO₄ effectively prevents the atmospheric corrosion of Al coupled to steels.