Galvanizing is a manufacturing process where steel or iron is coated with zinc. Galvanized steel, therefore, is zinc-coated steel. There are several galvanizing methods, with the most common method being hot dipped galvanization.
Galvanized steel is one of the most popular steels because it is rust-resistant and more affordable than most treated steels. Galvanized steel is low-maintenance and doesn't need refinishing. Thanks to its zinc coating, it's shielded from the elements, allowing it to endure for up to 50 years in moderate climates. Even when exposed to harsh weather conditions, galvanized steel can remain durable for more than 20 years.
Various methods are employed for galvanizing, including galvannealing, pre-galvanizing, electrogalvanizing, and hot-dip galvanizing. Among these, hot-dip galvanizing stands as the most widely used, and we'll delve into it in greater detail shortly. Before that, let's provide a brief overview of the other three methods:
Galvannealing: This method combines hot-dip galvanizing with annealing to create a dull matte surface that is particularly suitable for welding and painting.
Pre-galvanizing: In this process, the metal is primed with a cleaning agent and swiftly passed through molten zinc, resulting in a more uniform coating compared to standard hot-dip galvanizing.
Electrogalvanizing: Unlike the use of molten zinc, this method involves covering the steel with an electrolyte solution followed by the application of an electric current, ultimately bonding the zinc to the steel surface.
In the hot dip galvanizing process, steel is immersed in molten zinc at high temperatures. Within the molten zinc, a metallurgical reaction takes place between the iron in the steel and the hot zinc. This reaction, known as a diffusion process, causes the coating to form uniformly perpendicular to every surface.
Upon removal from the zinc bath, the steel reacts with oxygen in the air to create zinc oxide. Subsequently, it reacts with carbon dioxide to form the final protective layer of zinc carbonate. This process results in the steel acquiring a multi-layered coating comprising zinc metal and iron-zinc alloy, providing excellent corrosion resistance.
Hot-dipped galvanized steel displays a distinctive appearance compared to other galvanized steel types, featuring a mottled, crystalline-like pattern referred to as a "spangle" pattern.
Galvanized steel boasts remarkable versatility, finding use across various industries such as agriculture, automotive, construction, solar energy, telecommunications, and more. Its corrosion resistance makes it a preferred choice for applications exposed to moisture and environmental elements.
Various items such as screws, nuts, bolts, tools, and wires undergo galvanization to enhance their longevity. Galvanized steel is extensively utilized in entire steel-framed buildings to provide substantial structural support. Additionally, it's a common choice for constructing fences, roofs, staircases, and other architectural elements. Galvanized steel's versatility goes beyond functionality, offering aesthetic appeal as well. Architects frequently integrate it into their designs due to its shiny finish, which provides a clean, modern look highly favored in contemporary architecture.
In essence, hot-dipped galvanized steel is a category within galvanized steel. The hot-dip galvanizing process is cost-effective, resulting in a highly durable and versatile product. This type of galvanized steel is prominently employed in applications that confront environmental exposure due to its exceptional corrosion resistance.
