In the steel manufacturing industry, the durability and weatherability of steel products come first. The traditional batch galvanizing process enhances the steel’s corrosion resistance. However, here is the catch. Its advantages were limited to smaller components. Then, here comes the Continuous Galvanizing Process, a highly efficient and cost-effective process to apply the hot-dip zinc coating on steel products of every kind and shape. This process revolves around coating a thin zinc layer on both sides of steel sheets. Unlike the traditional batch galvanizing method, steel coils or sheets are constantly fed through a molten zinc bath, ensuring the quality and quantity of the coating uniformly.
The main goal of continuous galvanizing is to protect the steel from corrosion and rusty conditions and enhance the life span of your project’s structural integrity. The process usually starts with cleaning and heating, then coating, inspection, and cooling. Lastly, the corrosive-resistant steel is recoiled into a finished product. Interestingly, such durable steel products are widely used in various applications especially in the automotive industry, construction, HVAC systems, and agriculture, to electrical appliances. Given its prevalence in different industries, let’s delve into its potential benefits and understand how the Continuous Galvanizing Process works in the Steel Industries.
Core Benefits of Continuous Galvanizing
Galvanized Steel is a blend of durability and corrosion resistance. You must be wondering why people should choose Continuous Galvanizing among the different methods. The answer lies in the plethora of benefits of continuous galvanizing.
Let’s shed light on the comparative advantages of the process.
1. Enduring Corrosion Protection
Continuous galvanizing offers enduring corrosion protection by coating zinc layers on the steel products. Zinc is known for creating a protective barrier against moisture, air, and rusty conditions. Besides its anti-corrosive nature, zinc also acts as a sacrificial layer. In the case of any scratch on the surfaces, the zinc layer will corrode preferentially and protect the steel underneath, offering the best corrosive protection.
2. Strong Galvanic Protection
Compared to products that are cut from pre-galvanized metal, products that have been continuously galvanized exhibit strong galvanic protection. So the process helps to reinforce edge strength and protect against wear and damage.
3. Long-lasting Durability
Undeniably, galvanized steel is the showcase of durability and versatility. Moreover, it possesses the ability to withstand harsh weather and environmental conditions. The application of the zinc layer through the Continuous Hot Dip Galvanizing Process protects the steel for a long period, depending on the nature and thickness of the products.
4. Improved Coating Ductility & Adhesion
Batch-dipped steel products are brittle and do not withstand the pressure. On the other hand, a zinc coating through continuous galvanized coating is virtually 100% ductile-free and shows brilliant adhesive properties. A continuous hot-dip coating can readily be bent nearly 180 degrees without cracking or peeling.
5. Excellent Uniform Coating
Continuous galvanizing also ensures excellent uniform coating as compared to the traditional galvanizing process, elevating the quality, life span, and functionality of the steel.
6. Cost-effectiveness
At the core of advantages lies the cost-effective nature of the continuous galvanized steel. Being an efficient process, it allows large-scale production at small costs. By slashing labor costs and reducing waste during the process, the Continuous Galvanizing Process has emerged as the most affordable option in the industry.
7. Minimal Maintenance
Are you looking for a corrosion-resistant product with minimal maintenance requirements?
The steel wires and sheets that go through the continuous coating process offer little to no maintenance for long periods even in extreme weather conditions.
8. Environmentally Sustainable
Continuous galvanizing of steel is environmentally friendly, with low lead content and efficient energy use. The lead content in our coatings is below the standards, and the total energy used to galvanize the steel products is at least three times lower than comparable galvanizing processes. Moreover, being recyclable, both zinc and steel can be used without compromising on the quality.
Ongoing And Emerging Trends in Continuous Galvanizing with Impressive Statistics
Without providing insightful trends and statistics it is difficult to understand the importance of a process. According to a research study, 80 million tons of Galvanized Steel are produced globally each year. Around 50% of global zinc production is often used for anti-corrosion galvanizing processes. Continuous galvanizing can increase product durability by 30-50% compared to uncoated steel. In terms of industries, approximately 6m tonnes of zinc is produced for use in automotive, construction, and infrastructures. The global hot-dip galvanizing steel market was valued at $185 Billion and is expected to reach $230Billion by 2026 with an annual growth rate of 5%.
The market of continuous galvanizing is also exhibiting ongoing and emerging trends across diverse industries. For instance, continuous galvanizing has increasingly been used to coat advanced high-strength steels to meet the automotive industry’s unquestionable corrosion resistance requirements. The demand for galvanized products has grown by 10% annually in the renewable and solar panel sector. When it comes to global expansion and market monopoly, China holds supremacy with a 40% share in production. Owing to growing climate concerns, the shift towards sustainable continuous galvanizing has also gained momentum.
Continuous Galvanizing Line Process
Continuous Galvanizing is an efficient process used to cover the steel sides with zinc coating to improve corrosion resistance. The coating can be applied to different Types of Galvanized Steel including wires, sheets, and coils. The process consists of various steps ranging from surface preparation, annealing, galvanizing, and air wiping to quality inspection. Let’s discuss each step one by one for better understanding.
Cleaning
The first step starts with cleaning of the steel surface with an alkaline solution to remove any oxides and impurities that will reduce the adhesive capacity of zinc. The next step involves pickling with acid. Here the cleaned surface is washed with acids to remove the rust. After that, the surface is washed with water to rinse the traces of acid.
Heating
In this step, the steel is heated in an annealing furnace to match the temperature of zinc for effective bonding. This step improves the mechanical properties and enhances the galvanizing process.
Continuous Hot Dip Galvanizing with Molten Zinc Coating
The pre-heated steel strip enters a molten zinc bath. The temperature of zinc is usually maintained at 450C. The immersion helps in the formation of the metallurgical bond between steel products and zinc coating. This is the process that leads to corrosion resistance against rust.
Air Wiping
After leaving the zinc bath, the Galvanized Steel Sheet is passed through an air-wiping system to remove the excess coating on the steel. This step ensures the uniform coating on the steel products.
Cooling and Solidification
The zinc-coated strip is cooled by using the air-quenching system. Soon after the solidification of the zinc coating on the steel surface, the strip is processed through the mild cold rolling process to improve the surface finishes.
Surface Treatment
The galvanized steel undergoes various surface treatments involving chromating, oiling, and painting to enhance the resistance, and durability during storage, and protect the surface.
Quality Inspection & Recoiling
This is the last step where strips of steel sheets are packed and rolled in large rolls. Before the delivery, these rolls are inspected for quality assurance. Everything from coating, and finishing to packaging, is carefully checked.
Also Read About Hot Dipped Galvanized Steel
The Difference between Continuous Galvanizing and Batch Galvanizing
When it comes to galvanizing, a comparison is often drawn between continuous galvanizing and traditional batch galvanizing. Key differences are described as follows;
Thickness Coating
In continuous galvanizing, the thickness of the coating is often controlled by an air-wiping system which removes the excess zinc coating. On the contrary, in batch galvanizing, coating thickness depends on the thickness of steel, making it difficult to ensure uniformity.
Coating Consistency
Continuous Galvanizing produces a consistent coating of the zinc as compared to a batch where the coating could be uneven and thicker.
Formability
Continuous galvanizing forms a thin coating, making the steel products more suitable for formability. On the contrary, thicker coatings during batch galvanizing can be cracked, making it more difficult for bending purposes.
Applications of Continuous Galvanizing
Continuous Galvanizing offers numerous applications across different industries;
Automotive Industry
Galvanized steels are often used to make the body panels of cars, frames, exhaust systems, and suspension parts for better functioning.
Construction and Infrastructure
In the construction industry, Galvanized Steel Pipe is often used in steel framing of structural frameworks, cladding, and roofing to withstand the harsh weather. Plumbing used in construction often uses galvanized steel for longevity.
Agriculture
Galvanized steel is widely used for fencing, carrols, roofing, and siding materials for barns and agricultural sheds.
Appliances & HVAC systems
For appliances and HVAC systems, Galvanized steel is the best option as it is used in household appliances, HVAC components, and ventilation parts to withstand the moisture and pressure.
Advantages Over Other Coating Methods
Continuous galvanizing offers numerous benefits over other coating methods. The most distinguished feature lies in providing enduring corrosion resistance against harsh weather conditions. This kind of galvanizing ensures uniform coating thickness as compared to traditional batch galvanizing. Besides, one can also experience durability, formability, and cost-effectiveness by opting for a Continuous Galvanizing Process. It can also accommodate a variety of steel shapes from thin sheets to complex files, making it adaptable to different industries.
Tips To Choose the Right Coating For Your Steel Products
Choosing the right galvanizing method for your project requires a solid understanding of project specifications and performance characteristics of zinc coating on Galvanized Steel Coil. The ASTM A653 standard provides clear guidelines for zinc-coated steel sheet specifications, commonly used in various applications.
- ASTM A653 categorizes zinc coating weights in different designations like G60, G90, G115, etc.
- G60: Approximately 0.60 oz/ft² of zinc coating; suitable for indoor environments.
- G90: Approximately 0.90 oz/ft²; this coating weight provides moderate protection for outdoor or moderately corrosive environments.
- G115 and above Higher-grade zinc coatings offer even greater protection, ideal for severe outdoor or coastal environments.
- Project-specific considerations should be put in place to understand the budget constraints, aesthetic requirements, and longevity needs.
- For better results, always choose the zinc coating that corresponds to environmental conditions such as low exposure and moderate to severe outdoor exposure.
- Selecting the best galvanizing method that complements your steel product requirements.
Maintenance Tips for Long-term Durability
It is important to protect it against inclement conditions to enhance the lifespan of a Galvanized Steel Pipe. In the post-fabrication process, it is mandatory to inspect the susceptible areas of the steel products and look for any signs of wear and tear, showing the erosion of the galvanized layer. Single damage can expose the steel products to rusty conditions. After carefully assessing it, apply the touch-ups in the vulnerable areas to reduce the extent of damage. In this regard, high-quality zinc paint can act as an effective barrier. Such routine check-ups can enhance your product’s longevity in the long run.
Final Thoughts
The Continuous Galvanizing Process revolves around coating the steel products with hip-dip zinc coating. This is not a single step; in fact, this process comprises a series of steps involving cleaning, heating, galvanizing in a zinc molten bath, air-whipping, and solidification. Unlike the traditional batch galvanizing process, continuous galvanizing unlocks a plethora of advantages ranging from corrosion resistance, affordability, coating consistency, durability, and versatility to diverse applications. Given its unique and extraordinary benefits, you can use it in the automotive, agriculture, construction, and HVAC industries.
If you have made up your mind to protect your steel products from rusty conditions, look no further than Four Steels. We are the best and most Professional Stainless Steel Manufacturers and fabrication company in the United States.
For years, we have carried the legacy of dedication and trustworthiness to offer high-quality galvanized steel products. Whatever your need for your project, we are just one call away!