EFFECTS OF ZINC POWDER ADDITION TO VILLA GLOSS AND SILKA LUX MARINE ENAMEL PAINTS ON CORROSION RESISTANCE OF MILD STEEL

The most common method of protecting steels and other similar engineering materials from corrosion is by painting or coating. Development in the paint industries suggests that the modern paints exhibit improved corrosion resistance over their predecessors. However, anti-corrosion properties of the paints can further be optimized when adequate proportions of the paint constituents are used. Effect of zinc powder addition to Villa Gloss and Silka Lux Marine Enamel paints on corrosion resistance of mild steel was studied. The results indicate that zinc powder addition between 15 and 25 % significantly reduced the corrosion rate and thus increased the inhibition efficiency of mild steel immersed in seawater. The corrosion rate stabilizes at approximately 0.10 mmpy when zinc powder added was above 15 %, independent of the exposure time. Potentiodynamic anodic polarization curves of the samples immersed in seawater show that sample with 25 % zinc powder addition exhibited highest corrosion potential and the least corrosion current. Microstructural analysis of the samples also revealed the presence of pit corrosion at the surfaces of the samples and their geometry, volume fraction and distribution vary with the zinc powder addition.