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

Abstract

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/γ-Fe2O3 phase dominates the composition of the rust layers apart from a small amount of α-FeOOH and γ-FeOOH. γ-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 γ-FeOOH is higher in the rust layer under the high splash amount than under the low splash amount.