Corrosion behaviour of zinc coated steel in seawater

Abstract

This study investigated the performance of zinc coating as corrosion prevention for mild steel. Mild steel is the most versatile, least expensive and widely used but it is easily corrode when expose to aggressive environment like seawater. The objectives of this study are to know the effect of zinc coating towards rate of corrosion of mild steel in seawater and the effect of zinc coating toward corrosion of steel. In this review, reports the results of weight loss analysis, impedance analysis, morphology and surface analysis and lastly, the rate of corrosion of sample. The samples used in this study were fully zinc coated steel, zinc coated steel with scratch and mild steel as a control. The metals were immersed in seawater at room temperature for 40 days with IO days time intervals of characterization test. The results show that the corrosion rate of fully zinc coated steel decrease with time exposure from 0.03 mm/y to 0.0 I mm/y and for zinc coated steel with scratch, from 0.034 mm/y to 0.012 mm/y. furthermore, the result obtained from the impedance analysis, the resistance of samples increase with the time exposure. The findings reveal that the minimal rise in weight for fully zinc coated steel and zinc coated steel with scratch. Lastly, the results obtained lead to the conclusion that zinc coating is effective as corrosion protection for steel even with a presence of cut edge or scratch.