Corrosion

—Chemical action which causes destruction of the surface of a metal, usually by oxidation or rusting, often by the disintegrating influence ot stray electric currents or ground return currents in electric systems, known as electrolytic corrosion; the metal may be also eaten away by the action of acids present in water or in the surrounding air. To diminish corrosion of exposed surfaces, paints, oils, or other protective coatings are employed.