## 3 Results and Discussion
### Characterization of Steel Reinforcement Passivation Based on Dynamic Potential Polarization Curve  
The analysis of the polarization curves allows for an examination of the relationship between the electrode potential and the current density within a material system, providing crucial information about the corrosion behavior of the material. The polarization potentiodynamic method in this case was used to show what the behavior of the material is in the anodic region. Through kinetic parameters, what is the resistance of the material and whether there is a region of passivity under certain conditions can be understood. Thus, electrochemical polarization curve tests were conducted on the simulated solution of concrete in the soaking test to analyze the passivation process of steel reinforcements. By utilizing the electrochemical dynamic potential polarization method, a polarization curve of the steel electrode versus soaking time was obtained, as shown in Figure 7. Observing Figure 7, it is evident that the shift in the corrosion potential, E\({}_{\text{corr}}\), offers an indication of the level of passivation of the steel reinforcements. As the corrosion potential progressively moves in the positive direction, it indicates that the passivation film on the surface of the steel reinforcement electrode is forming and maintaining stability. Research by relevant scholars has shown that, compared to saturated calomel electrodes, the critical corrosion potential of steel electrodes is approximately \(-0.275\) V [36]. This research also showed that when the corrosion potential falls below this threshold, steel exhibits significant corrosion activity, with a corrosion probability exceeding 90%. Furthermore, the self-corrosion current density, i\({}_{\text{corr}}\), can be used to evaluate the passivation rate of steel reinforcements. When the corrosion current density is low, it indicates that the passivation film of steel reinforcements tends to stabilize. The critical corrosion current density of steel reinforcements in concrete is approximately \(0.2\)\(\mu\)A/cm\({}^{2}\), corresponding to the critical corrosion potential. These findings suggest that electrochemical polarization curve testing can effectively assess the passivation status and corrosion risk of steel reinforcements in concrete structures. By monitoring these key parameters, engineers and researchers can gain insights into the behavior of steel reinforcements in concrete and take appropriate measures to mitigate corrosion-related issues. Figure 6: The variation law of polarization resistance during the passivation process of steel reinforcements in concrete. In Figure 7, the corrosion potential (E\({}_{\text{corr}}\)) of the steel electrode is significantly higher than \(-\)0.275 V, which suggests that the steel electrode gradually forms an oxide film and remains stable in the simulated concrete environment. To provide a more detailed quantitative analysis of the passivation situation on the surface of the steel reinforcements, the Tafel polarization curve parameters of the working electrode were fitted using the extrapolation method. These parameters include the anode Tafel slope (b\({}_{1}\)), the cathode Tafel slope (b\({}_{2}\)), the Stern-Grey coefficient (B value), the working electrode self-corrosion current density (i\({}_{\text{corr}}\)), and the corrosion potential (E\({}_{\text{corr}}\)), which are presented in Table 2. The anode Tafel slope (b\({}_{1}\)) parameter reflects the anodic reaction rate on the steel surface, while the cathode Tafel slope (b\({}_{2}\)) parameter characterizes the cathodic reaction rate. The self-corrosion current density (i\({}_{\text{corr}}\)) parameter reflects the degree of corrosion activity on the steel surface, with lower values indicating lower corrosion activity. Finally, the corrosion potential (E\({}_{\text{corr}}\)) parameter represents the thermodynamic tendency towards corrosion, with a more positive value indicating a lower corrosion tendency.