Corrosion Performance of Zn-Si Electrodeposits on Steel: Effects of Preparation Conditions

RIP2025-00133: A wide array of electrodeposited coatings can be engineered, but achieving corrosion-resistant coatings requires intricate processes in which surface preparation plays a paramount role as a precursor to coating deposition. Consequently, a comprehensive evaluation of the influence exerted by mechanical and chemical surface treatments as preparatory stages for the electrodeposition process is essential for advancing the efficacy of this corrosion control methodology. In this context, the literature extensively discusses the application of electrodeposited coatings on steel substrates and their corrosion resistance. However, a notable knowledge gap persists regarding the specific effects of these surface preparation parameters on the behavior and performance of Zn-Si coatings, warranting further investigation. Addressing these challenges, the central objective is to systematically evaluate and enhance surface treatments for Zn-Si coatings, aiming to provide optimal performance while countering corrosion, thereby advancing the development of efficient, accessible, and utility of beneficial advanced coating technologies across industrial applications.

This study aimed to enhance the corrosion resistance of electrodeposited Zn-Si coated steel by evaluating mechanical and chemical surface treatments. The research involved two mechanical treatments, including i) wire wheeling (Method 1); and ii) polishing to 2000 grit (Method 2) and three chemical treatments, including the following combinations i) NaOH, HCl, and acetone (Method A); ii) muriatic acid (Method B); and iii) ultrasonic cleaning, NaOH and H2SO4 (Method C). The effects of the treatments were analyzed using surface and coating characterization, and electrochemical techniques. These included optical profilometer, contact angle measurements, scanning electron microscopy, exposure to ASTM B117, electrochemical impedance spectroscopy, and energy dispersive X-ray spectroscopy, and adhesion strength. The results revealed that polishing to 2000 grit combined with chemical cleaning steps employing NaOH, HCl, and acetone provided a surface that led to the best corrosion performance of electrodeposited Zn-Si coated steel.

This study provides further insights into optimizing surface treatments to improve the corrosion resistance and reliability of Zn-Si coated steel. By reducing the frequency of replacements, these advancements not only mitigate the environmental impact but also promote sustainability within the steel industry. Additionally, the extended service life of the steel leads to economic benefits, including lower maintenance costs and increased productivity in sectors dependent on corrosion-resistant materials. Moreover, this research lays a scientific foundation for the development of more effective corrosion-resistant coatings, contributing to the overarching objective of enhancing steel reliability across various industries.