Why should aluminum be used cautiously when near steel in a marine environment?

Aluminum should be used cautiously near steel in a marine environment primarily because it has a high potential in the galvanic series. This means that when aluminum comes into contact with steel, particularly in the presence of an electrolyte such as seawater, a galvanic cell is formed. In this cell, aluminum acts as the anode, which means it will corrode at an accelerated rate while the steel, acting as the cathode, becomes protected. This accelerated corrosion can lead to significant deterioration of the aluminum component over time, which can compromise the integrity and safety of marine structures or vessels.

In a marine environment where seawater acts as an electrolyte, the risk of galvanic corrosion increases significantly. Proper isolation techniques, such as using dielectric fittings or coatings, must be utilized to mitigate this risk when working with aluminum and steel in close proximity. Understanding the galvanic series is crucial for marine professionals to make informed decisions regarding material use and to protect against corrosion.