Abstract <p>In this study, Ni-Fe coatings with Fe contents ranging from 33 to 75 wt.% were electrodeposited from citrate-based electrolytes containing different ion mass ratios (Fe_mass:Ni_mass = 0.2 and 0.35). The surface morphology, microstructure, and electrochemical corrosion performance of the coatings were characterized and evaluated. The x-ray diffraction results indicated that as the Fe content increased, the microstructure transitioned from an FCC phase (Fe content: ~ 33-57 wt.%) to a mixed phase of FCC and BCC (Fe content: ~ 62-68 wt.%) and eventually stabilized into a BCC structure (Fe content: ~ 72-75 wt.%). Concurrently, the atomic force microscopy test results indicated that the surface roughness increased from 2.5 ± 0.2 to 44.3 ± 0.6&#xa0;nm, and the probability of crack formation also increased. The electrochemical corrosion results revealed a complex relationship between the Fe content and corrosion rate. Initially, as the Fe content increased, the corrosion rate of the coating decreased, followed by an increase at higher concentrations. The corrosion resistance was optimal when the coating exhibited a mixed-phase structure dominated by an FCC structure. Notably, the corrosion rate of the FCC/BCC mixed-phase structure, which was primarily composed of FCC, was 69-75% lower than that of the pure FCC structure. The corrosion morphology observed from the scanning electron microscopy results were in agreement with the electrochemical corrosion results. This study addresses a research gap by investigating the relationship between the microstructure and corrosion behavior and can be used as a guide for the optimization of the coating composition design for industrial applications</p> Graphical Abstract <p></p>