Corrosion science

Metals of many kinds undergo corrosion when they are exposed to air, water or other substances. An example is rusting of iron. Rusting weakens bridges, ship’s hulls, iron railings and car bodies. Hence rust prevention is an important task in any industry. Corrosion is a continuous process. Corrosion of a metal can be regarded as the reversal of its extraction. Corrosion will produce electrochemical changes on their surfaces. Dry corrosion involves the direct attack of metals by dry gases mainly through chemical reactions. Wet corrosion involves reactions in aqueous medium and is explained on the basis of electrochemical theory. The electrochemical changes here include formation of galvanic cells, anodic reaction and cathodic reactions.