“By applying multilayered protective zinc coating layers, the galvanizing process protects metals like steel or iron from rusting. It’s 10 times better than standard coatings and increases lifespan.”
Selecting the suitable metal is critical to any project, influencing factors like longevity, expenses, and project outcomes. Among the array of advanced surface finishing, galvanized metal stands out for its exceptional strength, durability, and malleability.
In this guide, we’ll explore the galvanization process in depth and then detail the significant benefits and versatile applications of galvanized sheet metal.
Galvanizing Defined
Galvanized sheet metal parts
The galvanizing process involves the coating of the surface of metals, alloys, or material with zinc to improve its appearance and protect it from rusting. This technique is widely used to increase the durability of metal parts because the zinc layer is sacrificial, thus protecting the base material.
Galvanized metal can be defined as metal that has undergone the process of galvanization, in which a layer of zinc is deposited on the surface to prevent rusting. Usually, this is done by submerging the metal in hot zinc to form a zinc layer with a chemical bond with the surface, thus providing a protective coating.
Many metals can be galvanized, but the most common ones are steel and iron. Ferrous materials, including cast steel, cast iron, malleable iron, hot rolled steel, and cold rolled steel, are usually galvanized. In contrast, nonferrous materials like copper or aluminum do not form galvanized coatings because of the galvanization process.
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Galvanizing Process
Galvanization is a protective process in which metals such as steel and iron are covered with zinc. This is done in the following ways: zinc, in the form of liquid or powder, is deposited on the surface of the metal.
Hot dip galvanizing process
In the galvanization process, zinc interacts with iron in the metal to produce tough alloy layers. This protective layer helps to protect the base metal from corrosive agents, including acids, alkalis, and gaseous environments, which in turn increases the life span of the base metal.
The galvanization process comprises three main phases: These include; cnc surface finish preparation, actual galvanizing, and post-treatment. It is crucial to prepare the surface correctly and to follow the correct steps after the galvanizing process to guarantee the functionality and aesthetics of the coating.
This protective zinc layer also acts as a sacrificial layer; if exposed, it corrodes faster than the base metal, thus protecting it from rust and corrosion. Other treatments, such as chromate, can improve galvanized metal’s protective features, which is why it is widely used in the construction, automotive, and manufacturing industries.
What is Galvanized Steel Metal?
Steel galvanized parts
Galvanized steel, a term frequently used in manufacturing, including metal stamping and spinning, is steel coated with zinc. This process improves the steel’s ability to resist corrosion. While regular steel can easily corrode when exposed to moisture, galvanized steel can retain its quality for a long time, regardless of the weather conditions. This coating helps to avoid the corrosion of the steel, which in turn increases its durability and usability for a longer time.
Different Approaches to Galvanizing
There are several types of galvanizing service that are used, and each has its properties and advantages. Let’s explore these methods:
Thermal Galvanization
Thermal galvanization or hot-dip galvanizing is a process of dipping the metal after proper cleaning into molten zinc. The zinc fuses with the metal substrate to form a metallurgical bond and thus forms a protective layer. This method is fast and cheap, but it may form layers with different thicknesses.
Pre-Galvanizing
Pre-galvanizing takes place during the first stages of steelmaking. Metal sheets are cleaned, passed through a zinc bath, and recoiled. Although this gives a uniform layer, it is possible to get exposed areas during other fabrication processes.
Electro galvanizing
Electro galvanizing employs an electrolyte solution and electric current to cause the zinc ions to adhere to the steel. This method gives accurate and consistent layers of the coating material but usually provides fewer layers than thermal galvanization.
Thus, each of the methods of galvanization has its strengths and weaknesses, and it is crucial to select the most appropriate technique depending on the project characteristics
Galvannnealing
Galvannealed steel sheet
Hot dip galvanizing and annealing are two processes used to produce special coatings on steel, referred to as galvannnealing. It entails immersing the metal in a zinc tank and then using an air knife to remove any excess zinc from the surface of the metal. Subsequently, the metal is exposed to heat treatment in a furnace and forms zinc-iron alloy layers. This results in a dull surface roughness, typically grey, and steel that can be readily welded with good paint bake-on characteristics.
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Benefits of Galvanizing
Galvanizing sheet metals offers a plethora of advantages that contribute to their long-term performance and cost-effectiveness:
- Prolonged Durability: The galvanization process provides long-lasting protection to metals so they do not rust for long. Galvanized steel can sometimes last up to 50 years or more before being repainted or touched up.
- Triple-layer Protection: The galvanization coatings protect the base metal in three ways: physical barrier, sacrificial protection, and protection against sideways corrosion. This all-around protection allows the metal to remain as it is, even in extreme conditions.
- Comprehensive Coverage: Galvanization protects all the faces of metals, blind faces, corners, and interior faces of the complex sections. This uniform coating provides dependable and durable anti-corrosion protection all over the structure.
- Robust Coating: The metallurgical bond developed between zinc and iron is very strong. It provides a protective layer not prone to rust, especially in areas such as undercuts and sharp edges. It provides a strong layer of protection to the metal and does not require other finishing processes.
- Cost-effectiveness: Galvanized sheet metal is economical in the long run because it is long-lasting and requires little or no maintenance. The fact that it is ready for use immediately and does not require further surface treatment also makes it cheaper in the long run.
- Swift Turnaround: Once the metal is ready and the zinc is molten, the galvanization process is fast and easy and takes only a few minutes. This is an advantage since businesses can complete projects within the required time and get results faster.
Galvanizing sheet metals is the best solution for enhancing durability, offering broad protection, cost-efficiency, and quick processing. That’s why it is widely used in numerous industries and construction.
Galvanized Steel Vs Aluminum: Which One Is More Favourable
Galvanized aluminum and steel are two of the most commonly used metals, each with unique characteristics for use in different fields. One of the most commonly used materials is galvanized steel, which is highly durable and does not rust easily; it is used in constructing automobiles, roofing, and fencing. On the other hand, aluminum has a low density and a high strength-to-weight ratio; thus, it is used in transportation, such as in aircraft, ships, railway cars, building parts, electrical equipment, and utensils.
Galvanized aluminum parts
Although galvanized steel and aluminum are used in manufacturing fan blades, galvanized aluminum sheets are preferred due to their lightweight. Nevertheless, the most popular choice for HVAC ducting and fan enclosures is galvanized steel sheets because of their low cost and ease of fabrication.
Comparing Malleability: Aluminum Vs. Galvanized Steel
As for ductility, aluminum is the clear winner since it is one of the most easily malleable materials that can be easily shaped and formed into different forms without compromising strength. On the other hand, although galvanized steel also has ductility to some extent, it is slightly less malleable than aluminum in terms of its ability to be shaped and formed.
In cases where a lot of shaping is required, complicated designs or configurations, aluminum is the most suitable material because of its flexibility. However, it should be mentioned that steel can be shaped quite freely when heated, though the work becomes more intricate in this case.
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Applications of Galvanizing
Galvanized metal is used in numerous industries because of its affordability and effectiveness in offering protective layers. Here are some of the key sectors where galvanized sheet metal is extensively used:
- Agriculture and Farming
Some of the uses of galvanized metal include; fencing, animal traps, gates, and any other structures used in farming. It is also resistant to corrosion; therefore, it can be used in areas where it will be exposed to weather conditions commonly found in farms to guarantee durability.
- Manufacturing and Industrial Equipment
In the manufacturing industry, galvanized metal produces industrial equipment, machinery parts, storage tanks, and conveyors. It prevents rusting and corrosion hence increasing the durability of vital equipment and structures.
- HVAC and Ventilation Systems
Galvanized sheet metal is used in the HVAC ductwork, ventilation systems, and air handling units. It is highly resistant to moisture and other environmental factors that make it suitable for heating, cooling, and air circulation.
- Transportation and Automotive
The automotive industry is one of the largest consumers of galvanized steel for producing automotive parts, truck bodies, trailers, and rail construction. It is a durable material that can withstand tough road conditions and moisture hence making vehicles safe and durable.
- Construction and Building Materials
In construction, galvanized metal is applied in roofing, cladding, structural beams, studs, and fasteners. Due to its ability to resist corrosion and its appearance, it is widely used in building houses and other buildings as a long-lasting and decorative architectural feature.
- Renewable Energy
Galvanized steel is vital in the renewable energy industry, especially in wind power and photovoltaic systems. Due to its ability to resist corrosion, it is ideal for use in outdoor conditions, thus the durability and efficiency of renewable energy systems.
In summary, due to its flexibility, strength, and relatively low price, galvanized metal is widely used in various fields, which leads to increased durability of various products.
Conclusion
The benefits of using galvanized metal include increased durability, protection from rusting, and reasonable prices. Due to its flexibility, it can be used in many fields and sectors of the economy. In cases where your projects require material that can endure rough conditions, then galvanized sheet metal is the best option.
When consulting on the choice of materials and the subsequent treatment of their surfaces, you can rely on Prolean. Our team is comprised of highly skilled personnel with vast experience in surface finish treatments and the best technology in galvanizing services. Call us today to make your design visions come to life with accuracy and quality.
We are a small research company. Can you coat zinc on stainless parts? We are looking for thickness of 50 µm.