How to prevent or reduce bimetallic electrocorrosion
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In the electrolyte, three test pieces of aluminum, copper, and iron were placed there, with the pieces in contact with each other. Aluminum was corroded very quickly, but in the same electrolyte, neither of the metals when placed alone nor when they were not in contact with each other suffered any corrosion. This indicates that the solution itself does not cause corrosion of metals; therefore, it is electrocorrosion. May I ask what methods or additives can be used to prevent or reduce this type of corrosion?
Looking back, the purpose of conducting this experiment is to compare the potential levels of metals... This can be determined without conducting an experiment by checking tables, so no extra time is needed. Moreover, understanding potential levels is primarily useful in industry for deciding on the appropriate materials to use. Finally, to avoid corrosion caused by potential differences, it’s necessary to first understand the principle behind such corrosion: a potential difference, an electrolytic solution, and metal in contact with each other... Once this is understood, the problem can be addressed at its root—by removing the electrolytic solution; there’s no need to add any special chemicals.
(1) Introduce a third metal with an even more negative potential, which serves for cathodic protection. *Power plant titanium condensers address the issues associated with rubber linings being damaged in carbon steel tubular boxes, as well as tube sheet explosions; Ti is used for composite welding, and a special aluminum anode is employed for this purpose. (2) Proper insulation can prevent galvanic corrosion. (3) The additive is used during the chemical cleaning process (over several dozen hours).