Electrodeposited coatings are one method used across automotive, infrastructure, and manufacturing sectors to protect steel components from corrosive environments. Their performance, however, is impacted by the sequence and quality of surface preparation steps applied prior to deposition, as these stages impact cleanliness, surface energy, and the initial conditions for nucleation and coating growth. Improper or inconsistent pretreatment can lead to defects, poor adhesion, and reduced service life. This establishes the industrial importance of maintaining reliable, sustainable, and efficient surface-conditioning practices. While extensive literature examines Zn alloy deposits, a notable gap persists regarding how specific mechanical and chemical surface preparation routes affect the morphology, and corrosion behavior of Zn–Si coatings. Addressing this gap is essential for improving coating reliability, reducing maintenance cycles, and supporting long-term sustainability objectives in sectors where corrosion-induced material loss imposes economic and environmental burdens. This study investigates the effects of mechanical and chemical surface preparation on the morphology and corrosion behavior of Zn–Si electrodeposited coatings applied to AISI 1008 steel. Multiple surface-conditioning methods were evaluated, including wire wheel abrasion, SiC grinding, and chemical activation sequences. Characterization via SEM/EDS, optical profilometry, contact angle analysis, bend testing, and accelerated cyclic corrosion testing using a modified version of SAE J2334 Standard, demonstrated that substrate condition strongly determines coating uniformity, nucleation density, and electrochemical stability. The latter was evaluated using Linear Polarization Resistance (LPR), Electrochemical Impedance Spectroscopy (EIS), and Anodic Potentiodynamic Polarization. The optimal chemical pretreatment incorporated a combination of acetone in ultrasonic bath for 5 mins at 23 ± 2°C, a hot alkaline bath (50 g/L NaOH) at 80 ±2°C for 5 mins, followed by an acid bath (10% H₂SO₄) for 5 sec at 23 ± 2°C, which produced the coating with the densest microstructure and highest corrosion resistance. Together, these findings confirm that surface preparation is a factor that controls the corrosion performance of Zn–Si electrodeposits. By improving coating integrity and corrosion resistance, pretreatments can contribute to longer component lifetimes and reduced material waste, supporting industrial sustainability goals.
