<p>This study is dedicated to the application of an eco-friendly pickling-free process in hot-dip galvanizing, wherein the oxide scale on the surface of hot-rolled high-strength steel is converted into a dense pure iron layer. The modulating effects of this dense iron layer on the adhesion and corrosion resistance of hot-dip galvanized coatings are systematically investigated herein. Systematic characterizations, including scanning electron microscopy (SEM), electron probe microanalysis (EPMA), X-ray diffraction (XRD) analysis, bending tests, electrochemical corrosion tests, and neutral salt spray tests, were conducted to investigate the morphological characteristics of the three states and their regulatory effects on coating performance. The results indicate that the structural state of the dense iron layer exerts a significant influence on the bending adhesion and corrosion resistance of the galvanized coating. Specifically, the continuous dense iron layer enhances coating adhesion by mitigating bending stress through internal fracture; the discontinuous dense iron layer exhibits optimal electrochemical corrosion resistance due to the formation of a dense corrosion product layer; and both the dense iron layer and the Fe₂Al₅ inhibition layer on its surface synergistically improve salt spray corrosion resistance by blocking the penetration of corrosive media. During the neutral salt spray corrosion process, ZnO is initially formed on the coating surface, which is subsequently transformed into Zn₅(OH)₈Cl₂·H₂O and a small amount of Zn₅(CO₃)₂(OH)₆ under the action of Cl⁻ ions. Furthermore, the free-standing discontinuous dense iron layer provides additional protection for the underlying coating.</p>