What is Galvanization? Hey Engineering Lovers, if you've ever heard the term “Galvanized Steel” or perhaps you've had to buy some type of galvanized material, have you ever wondered what exactly this galvanization process is? If you've ever asked yourself this question, this video is for you.
And rest assured that this process has nothing to do with any Galvão. (some Galvão Bueno meme) But before I tell you how galvanization works, take the opportunity to subscribe if you are not already subscribed, leave your like, and activate the notification bell and if you find our content interesting, consider becoming a member for us help continue producing content here on the platform and be remembered in our videos. Galvanizing is an industrial process used to protect metals against corrosion.
This technique involves applying a layer of zinc to the surface of the base metal, usually steel. Corrosion is a natural process in which metals, such as iron, react with environmental elements, such as oxygen and water, forming oxides that weaken and degrade the metal over time. This is a significant problem in many industrial applications, especially in construction and metal parts manufacturing , where durability is essential.
That's where galvanizing comes into play. We have a video that talks about this corrosion process, also known as rust, and I will leave a link to that video at the end of this one. But let's start at the beginning, who invented Galvanization?
The galvanizing technique, as we know it today, was developed by several scientists and engineers. A significant milestone was the work of Luigi Brugnatelli, an Italian chemist who in 1805 used the voltaic pile developed by Alessandro Volta to perform gold electrodeposition. This process at the time was called electroplating.
Hot dip galvanizing, the most common process used in industry today, was developed by Stanisław Soreau in 1837. But what exactly does this galvanizing process look like? It is important to understand that this process is divided into a few key steps.
Before galvanizing, the metal surface is prepared by removing any dirt, oxidation or old coatings. This is usually done through chemical cleaning and, in some cases, abrasive blasting. After this preparation step, the metal part that we want to galvanize is immersed in a bath of molten zinc at a high temperature, generally between 440°C and 465°C.
As a result, the molten zinc adheres to the metal surface. This causes the zinc to form a coating layer on the surface of the metal and it is this layer of zinc that protects the base metal against corrosion. After immersion, the part is cooled to solidify the zinc coating and is then inspected to ensure that the galvanizing was applied evenly and without defects.
If we think about it, it is a relatively simple process, but controlling the temperature of the zinc bath and the contact time is essential to ensure the quality of the final product. The zinc layer ends up functioning as a protective barrier, preventing oxygen and moisture from coming into direct contact with the base metal. This prevents corrosion, significantly increasing the useful life of galvanized metal parts.
Additionally, zinc is more reactive than iron, so if there is any damage to the plating surface that exposes the base metal, the zinc will serve as a sacrificial anode or as we call it, a sacrificial metal, corroding the zinc before of the base metal, providing additional protection. And does this galvanization work with any metal? Well, zinc galvanizing is most commonly applied to ferrous metals such as steel, however, galvanizing can be applied to other metals, although the specific process and coating metal may vary.
Other metals that can be galvanized include aluminum, copper, brass and even nickel. Aluminum galvanizing involves a different process called anodizing, in which an oxide layer is formed on the surface of the aluminum and this helps protect the aluminum against corrosion. Copper can be galvanized using a technique known as electrodeposition, the same one invented by Brugnatelli in 1805.
This can be done to protect copper against corrosion or to improve its appearance. Brass, which is an alloy of copper and zinc, can be galvanized to protect the zinc layer on the surface against corrosion. And nickel plating is a common process to protect nickel-based metal objects from corrosion and improve their appearance.
And is there any metal that cannot be galvanized? Most metals can be galvanized in some way, as long as the appropriate conditions and techniques for the process are met. However, some metals are more difficult to galvanize due to their chemical and physical properties.
An example of this is aluminum, where the anodizing process is much more complicated and requires the metal to be immersed in a series of tanks and in one of these tanks the anodic layer is created from the aluminum itself. Additionally, some rare or exotic metals may not be viable for galvanizing due to cost reasons or limited resource availability. Each metal may require a specific galvanizing process, and some may not be economically practical due to these factors and in these cases, some alternative solutions may be applied.
And what are the main applications of galvanized metals? Some automotive parts, such as the body, chassis, exhausts and internal components, are often galvanized to protect the metals against corrosion. Vessels, ships and offshore platforms often use galvanized steel to withstand constant exposure to salt water.
Some metal electricity poles and transmission towers are usually galvanized to withstand the harsh weather conditions of the environment. We also have galvanized pipes, which are used for water piping, sewage systems and electrical conduits, providing durability and corrosion resistance. Some metal structures used in warehouses, sheds and hangars can also go through the galvanization process.
If you've ever traveled around you'll have seen the guardrails, signposts and safety barriers on the roads, they are galvanized to resist weather exposure and impact. These are just some of the many applications of galvanized metals. This type of process plays a fundamental role in a wide range of industrial and engineering sectors, and it helps to extend the life of metal components and reduce maintenance costs due to corrosion.
So, did you know this galvanizing process? Have you ever worked somewhere that applies galvanization to steel? Leave it here in the comments and I want to know.
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