Nowadays continuous hot-dip galvanizing is widely used in metallic structures to protect steels against corrosion. Zinc provides a protective barrier thanks to the formation of a surface oxide and a sacrificial protection effect due to its high electroneg-ativity. However, structure manufacturing processes or mechanical assemblies by plastic deformation can create damage affecting the corrosion performance of the coating. The objective of the present work is to study changes of corrosion resistance induced by plastic deformation at room temperature. Uniaxial tensile tests combined with local strain measurements by image correlation were achieved. Specimens were deformed in air at different plastic strain levels. After mechanical tests intergranular cracking was observed by SEM. Electrochemical impedance spectroscopy (EIS) measurements at OCP (Open Circuit Potential) in 0.6M NaCl were performed on unstrained and strained specimens during 15 days. EIS diagrams evolution shows the detrimental effect of plastic deformation on the coating corrosion resistance for high deformation level related to the initial coating damage.
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