Effect of splash amount on corrosion of low-alloy steel in marine splash zone

Splash corrosion of Q345D low-alloy steel was simulated using a simulation apparatus where in-situ electrochemical measurements were performed. In the early stage of splash corrosion, the corrosion rate in the low splash zone is far higher than that in the high splash zone, and in the later stage only slight difference in corrosion rate can be observed under different splash amounts. Compared to the high splash amount, the corrosion under the low splash amount is more localized. The densities of rust layers in the splash zone increase with time, and Fe3O4/& gamma;-Fe2O3 phase dominates the composition of the rust layers apart from a small amount of & alpha;-FeOOH and & gamma;-FeOOH. & gamma;-FeOOH is mainly concentrated in the outer layer of corrosion products. Due to the obstruction of the denser rust layer in the low splash zone in the early stage to the transfer of Fe (II) species, the ratio of & gamma;-FeOOH is higher in the rust layer under the high splash amount than under the low splash amount.

Automated summary

Simulated splash corrosion of Q345D low-alloy steel and conducted in-situ electrochemical measurements. In the early stage of splash corrosion, the corrosion rate in the low splash zone is significantly higher than that in the high splash zone, but the difference in corrosion rate becomes slight in the later stage under different splash amounts. Compared to high splash amount, corrosion under low splash amount is more localized. The density of rust layers in the splash zone increases with time, and the rust layers are mainly composed of Fe3O4/γ-Fe2O3 phase with a small amount of α-FeOOH and γ-FeOOH.