Introduction
Steel is one of the most widely used materials in the world (80 million tons are produced in the USA). It is valued for its strength, versatility, and durability. However, steel is highly susceptible to corrosion without proper protection, which can be costly and lead to structural failure, increased expenses, and shortened product lifespans.
The construction, automotive, energy, and marine industries rely on advanced coating technologies to safeguard steel components against harsh environments.
Zinc provides a critical defense, forming a protective barrier against moisture, chemicals, and extreme temperatures.
Whether Hot-Dipped Galvanized Steel, Electrogalvanized Steel, Aluminized Steel, Galvannealed Steel, or Galvalume Steel, the right coating can significantly extend the life of steel products while maintaining performance and appearance.
This blog will explore the different types of zinc coated steel, their unique benefits, and how various industries use them to enhance longevity, safety, and cost-effectiveness.
Alliance Steel understands that successful metal processing starts long before fabrication. As an ISO 9001:2015-certified flat-rolled steel supplier, coil processor, and material distributor, we source materials exclusively from trusted suppliers and verify compliance upon arrival. Our advanced testing and inspection equipment ensures that every product meets or exceeds customer specifications, and every order is thoroughly audited for accuracy before shipment.
We supply various coated steel sheet and coil products, including hot-dipped, electrogalvanized, aluminized, galvannealed, galvalume, and Pre painted steel. Our value-added service capabilities include slitting, blanking, stretcher leveling, and metallurgical support.
The Role of Zinc
Zinc coatings play a crucial role in protecting steel from corrosion. When exposed to the atmosphere, Zinc reacts with oxygen to form zinc oxide, which then combines with carbon dioxide to create zinc carbonate—a stable layer that helps prevent further corrosion. This natural self-healing property allows Zinc to protect the underlying steel from environmental elements continuously.
Additionally, unique characteristics of Zinc include:
Galvanic Protection (GALVANIZING): Zinc is more reactive than iron or steel, so when a zinc coating is applied to steel, it acts sacrificially, corroding preferentially to protect the underlying steel. This process, known as galvanic or cathodic protection, helps prevent corrosion of the steel substrate.
Self-healing/ Barrier Properties: Zinc coatings have self-healing properties due to the formation of zinc oxide or zinc carbonate corrosion products. If the zinc coating is scratched or damaged, these corrosion products can react with the surrounding environment to form a protective layer.
Adhesion: Proper surface preparation and application techniques are essential to ensure adhesion between the zinc coating and the substrate.
Zinc coatings adhere well to steel surfaces, providing long-lasting protection against corrosion.
Versatility: Zinc coatings can be applied to the substrate material using various methods. This versatility protects multiple steel structures and components in different environments, from industrial facilities to outdoor infrastructure.
Coated Steel Products:
Alliance Steel offers a variety of coated steel coil and sheet products and value-added services to meet the needs of our custom customers.
Alliance Steel supplies coated steel in a wide range of thicknesses and widths for coil and sheet products. Coated steel products provide corrosion resistance properties and are also press formable, weldable, and printable.
- Hot-Dipped Galvanized Steel—Hot-dipped galvanizing (HDG) immerses the material into a bath of molten Zinc to create a protective layer against corrosion. First, the material must be cleaned to ensure a quality bond is made between the base metal and the zinc coating. Second, it's dipped into a liquid bath of heated Zinc, where a metallurgical bond is formed between the iron in the steel and the molten Zinc. This forms a sequence of intermetallic layers on all surfaces.
- Electrogalvanized Steel - Electrogalvanized steel is carbon steel with a corrosion-resistant zinc coating applied to one or both sides by electro-deposition. The continuous electrolytic coating process covers the steel surface with an exceptionally uniform thickness, which can enhance forming and joining operations. The process is ideal for applications where exceptional uniform thickness is paramount.
- Aluminized Steel is carbon steel coated on both sides with an aluminum-silicon alloy during the hot-dipped process. This creates a bright appearance and offers heat resistance at a competitive price. It is suitable for high-temperature, corrosion-resistant applications that do not require a high strength-to-weight ratio.
- Galvannealed Steel - Galvannealed steel is carbon steel coated with Zinc using the hot-dipped process. The steel is then annealed, converting the Zinc into a zinc-alloy coating with increased corrosion and scratch resistance.
- Galvalume Steel is carbon steel coated with an aluminum-zinc alloy using a continuous hot-dip process. It combines the corrosion protection and high-temperature resistance of aluminum with the formability and galvanic protection of Zinc.
Applications for Coated Steel Products
Coated steel is ideal for customers seeking an economical and effective way to protect steel from corrosive environments. The zinc coating is a barrier between the steel and the elements and will also sacrifice itself to protect the underlying steel.
Industries that use coated steel products include:
- Automotive
- Pipe and Tubular
- Outdoor Recreation
- Agriculture
- Construction
How Different Industries Benefit from Zinc Coated Steel Products
Different industries benefit from specific coated steel sheet and coil products based on their unique environmental challenges and performance requirements.
Construction & Infrastructure
Hot-Dipped Galvanized Steel, Electrogalvanized Steel, Galvalume Steel
- Used in bridges, highways, guardrails, and structural components to prevent corrosion from weather exposure.
- Barrier and sacrificial protection extend the lifespan of steel structures in urban and coastal environments.
Automotive & Transportation
- Provides thin, uniform zinc coatings for car bodies, preventing rust while maintaining paint adhesion.
- Used in exhaust systems and heat shields due to its superior heat and corrosion resistance.
Marine & Offshore
- Essential for docks, ship hulls, offshore platforms, and marine equipment to withstand saltwater corrosion.
- Galvanized Transmission Towers & Poles
- Prevents corrosion in electrical grids and wind farms exposed to outdoor elements.
Agriculture & Food Processing
- Aluminized & Galvanized Steel
- Used in grain silos, barns, irrigation systems, and food processing equipment to prevent rust and bacterial contamination.
In Conclusion
Steel remains vulnerable to environmental elements without proper protection, which can reduce its lifespan. By selecting the right coated steel, OEMs and fabricators can add durability, performance, and long-term value to their steel products.
Alliance Steel offers various coated steel solutions, including hot-dip galvanizing, electrogalvanized, aluminized, and galvalume steel sheets and coils. Each is designed to withstand harsh conditions and extend the lifespan of steel structures. Whether in construction, automotive, energy, or manufacturing, choosing the right steel coating is an investment in longevity and reliability.
Ready to find the best coated material for your steel application?
Contact Alliance Steel today to learn more about our coated steel products and how they can add value to your project.
