HOW DOES CORROSION FORM ON A METAL BODY?
Requirements for Corrosion Corrosion is nature’s method whereby metals and alloys return to their un-refined naturally occurring forms as ores and minerals. Metals such as iron, nickel, zinc, aluminum and copper occur naturally as oxides as well as sulfides and carbonates (meaning they are combined with the elements oxygen, sulfur or carbon and oxygen). When ore is refined this natural and most stable state (ore) is reversed to produce the actual metal which is less stable under natural conditions than the ore. A large amount of energy is applied to the ore (blast furnaces etc.) as the metal is converted from its oxide, carbonate, sulfide etc. Given the right conditions and following the law of entropy (DEFINITION: ENTROPY IS THE NATURAL TENDENCY OF ALL SYSTEMS TO PROCEED FROM AN ORDERED AND LESS STABLE STATE TO A MORE DISORDERED AND MORE STABLE STATE) these high energy and more ordered metals tend to revert to their low energy state and less ordered ore condition. Thus with most metal
