Corrosion of Aluminized Steel in Seawater

The influence of flow rate of seawater on the corrosion rate of hot-dipped aluminized steel in seawater was investigated using the following galvanic couples: aluminum/carbon steel, aluminum/Fe-Al alloy, aluminum/stainless steel, Fe-Al alloy/carbon steel, Fe-Al alloy/stainless steel, and carbon steel/stainless steel. The corrosion rate of aluminum in all the couples was greater than that of aluminum not connected with other metals. The corrosion rates increased in the following order: aluminum/carbon steel > aluminum/stainless steel > aluminum/Fe-Al alloy. Aluminum connected with carbon steel had the greatest corrosion rate: seven times of the rate of aluminum that was not connected with other metals. The galvanic corrosion rate of carbon steel is 1.9 to 2.5 times greater than that of carbon steel that is not connected with other metals.