Galvanic corrosion of Q345 steel in seawater under varying dissolved oxygen conditions

The galvanic coupling corrosion behaviour of Q345 steel in seawater with different dissolved oxygen contents (DOC) was investigated in this paper by using self-designed detachable electrodes fabricated as chain electrodes, and by using immersion and electrochemical methods in combination with macroscopic and microscopic corrosion morphology. Compared with the corrosion of the chain electrode in the non-electrically connected state, in the electrically connected state, the corrosion current densities of the corresponding electrodes were smaller and the R p values were larger when the DOC was 8.50, 7.50 and 5.50 mg L −1 , indicating that the corrosion reaction was mainly a self-corrosion reaction when the DOC was 8.50, 7.50 and 5.50 mg L −1 . When DOC is 9.50 and 6.50 mg L −1 , the corrosion current density of the corresponding electrode was larger, the R p value was smaller, the corrosion products on the surface of the electrode had a loose structure, the relative content of iron was higher, and the corrosion reaction was mainly galvanic coupling corrosion reaction.