*3.4. Electrochemistry*

The polarization curves of S-Cast and S-Defect in artificial seawater are shown in Figure 10.

The electrochemical corrosion parameters obtained by fitting a linear polarization region of approximately 10 mV around the resting potential are shown in Table 5.

The corrosion potential and corrosion current density of S-Defect are −86.31 mV and 0.23 <sup>μ</sup>A·cm<sup>−</sup>2, respectively, while those of S-Cast are −3.83 mV and 0.228 <sup>μ</sup>A·cm-2, respectively. Generally, defects decrease the corrosion potential and increase the corrosion current density. Defects increase the tendency toward galvanic corrosion of UNS C95810, which leads to the promotion of the corrosion driving force, thus accelerating corrosion. Therefore, S-Defect has a lower corrosion potential and a larger corrosion current density than those of S-Cast.

**Figure 10.** The polarization curve of S-Cast and S-Defect.

**Table 5.** Corrosion parameters of S-Cast and S-Defect.

