When galvanized stainless steel was making its premiere across the globe in the mid-1800s, it was mostly used to produce such items as wall ornaments, roof ornaments, window hoods and decorative shingles. The practical applications for galvanized stainless steel have increased exponentially over the years. For example, galvanized steel is used in the manufacturing of sheet metal that can be used to create nails, gutters and downspouts, according to the General Services Administration. Galvanized steel has wide applications in such industries as construction and agriculture.
Stainless steel has to undergo one of several possible processes to become galvanized, according to the General Services Administration. Immersing steel into a molten zinc bath is referred to as “hot dip” galvanizing. Dipping steel into an electrolyte solution coats steel with zinc and is referred to as “electro-galvanizing.” The thickness of the zinc coating is easier to control in the electro-galvanizing method. The process of sherardizing involves placing a given amount of steel in a vacuum environment where it gets surrounded with zinc dust and heated. The heating bonds the zinc to steel. Zinc can also be applied with special paints.
The overall effectiveness of galvanized stainless steel is heavily dependent on environment and the quality of zinc processing. Galvanized stainless steel is a durable material that can last for more than a century. In more rural areas where automotive emissions and pollution are at a minimum, galvanized stainless steel can last for well over 150 years. Even under conditions that promote corrosion, galvanized stainless steel can still hold up for between 50 and 100 years.
Despite the many benefits associated with galvanized stainless steel, there are some disadvantages with this material. The zinc galvanized surface of galvanized stainless steel can deteriorate gradually over time. The effectiveness of the galvanized surface of galvanized stainless steel depends on the thickness of the zinc application and the method of application (electro-galvanizing is more effective than hot-dip). Abrasion can wear down galvanized stainless steel's zinc coating, making it vulnerable to corrosion.
General fatigue can increase galvanized stainless steel's deterioration rate. Zinc coatings are vulnerable to expansion and contraction. According to the American Galvanizers Association, steel corrosion costs the economy roughly 3 percent of the country's gross domestic product annually. This is one of the largest reasons that galvanized stainless steel is employed in construction projects.