According to the World Corrosion Organization, corrosion around the globe causes damage of $2.5 trillion USD annually. A technical article, Corrosion is a Powerful Destructive Force. Prevention is Key highlights this statistic and explains how money can be saved by preventing this corrosion:
…including the cost of lost productivity because of outages, delays, failures, and litigation; labor; and new equipment to replace failed parts, directly improves profitability.
In the United States petrochemical refining industry, its:
…annual direct cost of corrosion is estimated at $3.7 billion. Of this total, maintenance-related expenses are estimated at $1.8 billion, vessel turnaround expenses at $1.4 billion, and fouling costs are approximately $0.5 billion.
Stainless steel and coated ferrous metals are used in most industrial electric products. Ferrous metals are quite susceptible to corrosion. Coatings:
…must be applied properly and protected against damage during installation and use. The zinc surface on galvanized steel serves both as a protective coating and, if damaged, a sacrificial anode that will corrode in preference to the exposed steel.
The galvanization process for iron and steel products:
…can greatly improve corrosion-resistance in wet or weather-exposed environments. In particular, galvanized cast iron and nonstainless steel products are often used in wet and weather-exposed locations with the expectation that they can safely remain in service for many years.
This process:
…creates a metallurgical bond between the zinc coating and the underlying steel or iron. This bond provides much stronger adhesion than any type of paint, including epoxies. The galvanized surface forms in multiple layers, with zinc and iron alloyed in varying ratios. The outer layer of pure zinc is relatively ductile, while the inner layers are progressively harder – harder than steel, in fact. These qualities combine to provide excellent resistance to both impact and abrasion, helping protect against surface damage.
Another approach is to use an epoxy powder coating. It:
…uses an electrostatic process to apply a finish to metallic parts in a dry state. Once applied, the finish is heat-cured to create a finish that is thicker, tougher, more even on all outer surfaces and edges, and more durable than most paints. This makes epoxy powder coat one of the preferred protection choices for oil and gas, wastewater and other harsh, corrosive industrial applications.
The article highlights using a triple coating as the best defense against corrosion. These coats include a zinc electroplate followed by a chromate dip, followed by an epoxy powder coat.
Read the technical article for more on testing performed on Appleton electrical products and for more on these coating methods. Visit the Appleton section on Emerson.com for more on the corrosion protection built into Appleton products.
