## 3 Results and Discussion
### Films Formed by Cyclic Voltammetry
It should also be noted that the intensity of the chromium oxidation peak with the increasing number of cycles suggests the progressive formation of an isolating oxide layer like Cr\({}_{2}\)O\({}_{3}\), which decreases the reactivity of the passive layer. At more positive potentials, we observe an intense increase in the current density due to the well-known water decomposition process generating an evolution of oxygen [38]. The reduction peak at 0.29 V vs. SCE, whose intensity increases with the number of cycles, corresponds to the reduction process of Ni\({}^{2+}\) to Ni\({}^{3+}\)[35; 36]. The voltammograms (Figure 2B) obtained on Inconel 600 are also similar to those found in the literature [39; 40; 41; 42; 43] but are different from those obtained on AISI 304 and AISI 316 (Figure 2A). In Figure 2B, an intensity increase in the oxidation peak at 0.39 V vs. SCE and in the reduction peak at 0.30 V vs. SCE with the increasing number of cycles is observed. These two peaks are attributed to the transition process from Ni(OH)\({}_{2}\) to NiO(OH) and conversely [42; 43]. The intensity of the oxidation peak of Fe\({}^{2+}\) to Fe\({}_{3}\)O\({}_{4}\) at \(-\)0.86 V vs. SCE tends to decrease [37]. In our voltammograms, we do not find any chromium oxidation peak. Nevertheless, XPS measurements performed by [PERSON] et al. [37] on films formed by cyclic voltammetry on the surface of nickel-based alloys in an alkaline medium revealed the presence of chromium Cr\({}^{3+}\) in the film. The voltammograms in Zone 1 indicate that the films formed on AISI 304 are thicker than those formed on AISI 316. However, the fact that they are thicker does not necessarily mean that they are more protective. The values of the average residual current measured for AISI 316 and AISI 304 stainless steel are reported in Table 2. In the first cycle, it can be seen that the average residual current for AISI 316 (11.57 uA/cm\({}^{2}\)) is lower than that of AISI 304 (14.55 uA/cm\({}^{2}\)), suggesting that the passive film formed on AISI 316 is more protective than the one formed on AISI 304. This trend is confirmed during the following cycles. For example, in the twelfth cycle, there is a decrease in the average residual current for the two alloys (3.95 uA/cm\({}^{2}\) for AISI 316 and 6.88 uA/cm\({}^{2}\) for AISI 304). The barrier properties of the films are improved with the increase in the number of cycles, as shown in the literature [38]. The mean residual current measured for the Inconel 600 after twelve cycles (4.86 uA/cm\({}^{2}\)) was found between the one measured on AISI 304 and on AISI 316. This suggests that the film formed on Inconel 600 in a simulated concrete environment at ambient temperature is more resistant than those formed on AISI 304 but less resistant than those formed on AISI 316. To confirm these results, we used electrochemical impedance measurements to determine the overall system impedance for the three alloys after CV in an alkaline solution of NaOH at pH = 13. The measurements were made from 100 KHz to 5 MHz. In Figure 3, the Bode diagrams show the same trend for the three alloys. At low frequencies, the impedance measured for AISI 316 was higher than the one measured on Inconel 600, which displayed a higher impedance than AISI 304. These data confirm the previous results obtained with the average residual current measurements. Taken together, these elements seem to suggest that the Inconel 600, which is an alloy generally used in critical environments, is less efficient than AISI 316 at room temperature in an environment simulating reinforced concrete.