## 3 Results and Discussion
### The Effects of EPS Immersion in Fire Extinguishing Solution
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Immersion Time**} & \multirow{2}{*}{\begin{tabular}{c} **R\({}_{\text{s}}\)** \\ \(\Omega\cdot\)cm\({}^{2}\)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **CPE1** \\ \(\Omega^{4}\cdot\)**Q\({}_{1}\)** \\ **S\({}^{\text{n}}\)/cm\({}^{2}\)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **R\({}_{\text{ext}}\)** \\ \(\Omega\cdot\)**cm\({}^{2}\)** \\ **S\({}^{\text{n}}\)/cm\({}^{2}\)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **CPE2** \\ \(\Omega^{4}\cdot\)**Q\({}_{2}\)** \\ **S\({}^{\text{n}}\)/cm\({}^{2}\)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **R\({}_{\text{ct}}\)** \\ **S\({}^{\text{n}}\)/cm\({}^{2}\)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **W** \\ **S\({}^{\text{n}}\)/cm\({}^{2}\)** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **10\({}^{3}\chi^{2}\)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} \(\epsilon\)Z \\ \end{tabular} } \\ \hline
1 h & 14.23 & 7.91 & 0.693 & 357 & 2.19 & 0.909 & 1765 & - & 0.427 & 2.10 \\
36 days & 53.29 & 3.42 & 0.589 & 898 & 5.37 & 0.733 & 1935 & - & 0.498 & 2.23 \\
78 days & 187.1 & 1.48 & 0.581 & 1971 & 6.58 & 0.573 & 1972 & 8.9 \(\times\) 10\({}^{-4}\) & 0.338 & 1.94 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Equivalent circuit elements values for EPS immersed in FES. The SEM micrographs for the total surface and various zones from this surface, at various magnifications, are presented in Figure 14.  
After 78 days of immersion in FES, three areas could be distinguished on the sample surface: an area covered with a fairly thick crust (Zone B); an area from which the crust was detached, but on which another layer was deposited (Zone A); and a portion of zone B on which material had been deposited (the color was whiter because it was higher than the other zones). In all zones, the surface was very irregular with crystalline and non-crystalline deposits (the largest amount), thus explaining the replacement of the outer layer capacity with the constant phase element CPE2. The results of the EDS microanalysis of some zones in these areas are presented in Figure 15.  
The analysis of these data indicates that areas B and C had practically the same composition. The differences were in the limit of experimental errors, taking into account the fact that the surface on which the composition was evaluated was very small (0.0225 mm\({}^{2}\)) and the inhomogeneity of the surface. Considering the compositions presented in Figure 15 and the elemental mapping exhibited in Figures 16 and 17, the following observations can be made:  
* In zone A, the paint layer was most likely damaged, this can be stated based on the fact that the concentrations of phosphorus and zinc (which are part of the phosphate layer) were high. In this area, there were also elements from FES (carbon, sulfur, sodium)  
Figure 14: The microstructure of the EPS sample immersed for 78 days in FES. Figure 15: Compositions of different areas from the EPS sample immersed for 78 days in FES. and paint layer (carbon, calcium (CaCO\({}_{3}\))), according to the elemental mapping. Iron in the form of oxide or oxyhydroxide is found in relatively small quantities, being deposited after adsorption of the elements in the FES. * In zones B and C, the amount of oxygen was very high and came mainly from the composition of the paint layer and the adsorbed components from the FES. As the iron from corrosion products was only in extremely small quantities (1.3%), few traces could be observed in the elemental mapping,
* According to the elemental mapping, in these areas, chlorine was found in the form of NaCl and MgCl\({}_{2}\), while Calcium could be found in the form of carbonate (CaCO\({}_{3}\)).