*2.3. Immersion Test*

In order to ensure the accuracy of the experiments, the immersion experiments were conducted in duplicate, meanwhile, the specimens were 4 × 2 = 8, every set needed 4 specimens, and there were 8 specimens in total.

Considering the short electrochemical experiment period, the total immersion corrosion experiment lengthens the experiment period. The immersion test experiments were carried out in natural seawater for different total immersion times in the laboratory. The samples were immersed in natural seawater for 20, 40, and 80 days at room temperature.
