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Why Galvanize? Preventing Corrosion  The only way to prevent steel or iron from corrosion is to protect it. Fortunately, two reliable methods of protection exist. Barrier protection acts by isolating the metal from the electrolytes in the environment. Two important properties of barrier protection are adhesion to the base metal and abrasion resistance. Cathodic protection requires changing an element of the corrosion circuit, introducing a new corrosion element, and ensuring that the base metal becomes the cathodic element of the circuit. Hot-dip galvanizing provides excellent barrier and cathodic protection. Through the sacrificial anode method, a metal or alloy that is anodic to the metal to be protected is placed in the circuit and becomes the anode. The protected metal becomes the cathode and does not corrode. The anode corrodes, thereby providing the desired sacrificial protection. In nearly all electrolytes encountered in everyday use, zinc is anodic to iron and steel. Thus, the galvanized coating provides cathodic corrosion protection, as well as barrier protection. |
