Corrosion behaviour of chromium coatings obtained by direct and reverse pulse plating electrodeposition in NaCl aqueous solution

• DC and PC techniques are used to obtain chromium coatings.
• Pulse plating lead to chromium coatings with superior corrosion performance.
• Corrosion behaviour of chromium layers depends on cracking and wettability.
• Chloride ions penetrate through the chromium cracks towards the substrate.

In this work the corrosion performance in chloride media of chromium coatings obtained by direct current (DC) and pulse current (PC1 and PC2) was studied. The electrochemical corrosion behaviour of the layers was characterized by means of potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) techniques. Additionally, metal cation release and morphological evolution of chromium surfaces as a function of immersion time in chloride solution was analyzed. The obtained results show similar hardness values and a superior corrosion performance of PC2 coatings, which is related to their roughness, morphology, wettability and mainly, their crack absence.

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