According to a study initiated by NACE International that illustrates the broad and expensive challenge that corrosion presents, total annual corrosion costs in the United States rose above $1 trillion in the middle of 2013. At an estimate of over 6.2% of GDP, corrosion is one of the largest single expenses in the U.S. economy. Corrosion carries a very high price tag for the United States, only exceeded by health care.1 A 2001 U.S. government-sponsored study estimated the costs of corrosion for military systems and infrastructure alone to be about $20 billion annually.2 Most of the loss is due to the corrosion of iron and steel used in the fabrication of highways and bridges, transmission pipelines, storage tanks, automobiles, ships, sewer systems and the like. Corrosion costs money and lives, resulting in dangerous failures and increased charges for everything from utilities to transportation, and more.
In addition to their primary attribute of providing improved appearance, organic coatings play a crucial role in preventing corrosion of the substrates underneath. Paint formulators use three basic strategies to provide corrosion protection for metal surfaces: 1) coating as barrier technology to prevent oxygen and water from getting to the metal surface; 2) passivation of the metal surface using corrosion-inhibiting additives and/or pigments; 3) and galvanic protection using a sacrificial metal additive.