Galvanic corrosion is an electrochemical process where one metal corrodes preferentially when it is in electrical contact with another, in the presence of an electrolyte. This form of corrosion occurs because metals within the galvanic series have different potentials to liberate electrons, setting up a galvanic cell when coupled. The metal with the higher electron potential, known as the cathode, remains protected, while the one with lower electropotential, the anode, undergoes accelerated corrosion. Common in environments with conductive solutions, such as saltwater, this process significantly affects materials like aluminum when in contact with stainless steel.
The severity of galvanic corrosion depends on factors such as the area ratio between the anode and cathode, the conductivity of the electrolyte, and the presence of protective coatings. Metals close together in the galvanic series exhibit minimal effects, whereas those far apart experience more rapid deterioration. Engineering strategies to mitigate galvanic corrosion include isolation of metal contacts with non-conductive materials, selection of metals close in the galvanic series, and appropriate application of sacrificial anodes or protective coatings. These preventive measures are crucial in industries like maritime, automotive, and construction to enhance the durability and integrity of metal structures and components.
