Electro Galvanized Coil Production Process

The production process for electro-galvanized coils involves applying a thin layer of zinc to steel coils through an electroplating process. Here is an overview of the typical electro-galvanized coil production process:

Steel Coil Preparation

High-quality steel coils, typically made from carbon steel, are selected for the electro-galvanizing process.
The coils may undergo cleaning processes, such as pickling, to remove any rust, scale, or oxides from the surface.

Surface Activation

The cleaned steel coils are subjected to a surface activation process, which involves the application of chemicals or a zinc ammonium chloride solution. This activation step helps improve the adhesion of the zinc coating.

Electroplating Bath

The activated steel coils are immersed in an electrolyte bath containing a zinc solution.
An electric current is passed through the bath, causing the zinc ions to be deposited onto the steel surface, forming a thin layer of zinc coating.

Formation of Zinc Coating

The zinc ions migrate to the steel surface and react, forming a metallurgical bond with the steel substrate.
The thickness of the zinc coating is controlled by adjusting factors such as the current density, plating time, and bath composition.


After the electroplating process, the coated steel coils are rinsed to remove any excess electrolyte solution.


The coils are dried to eliminate any remaining moisture.

Passivation (Optional)

Some electro-galvanized coils may undergo a passivation process to further enhance corrosion resistance. Passivation involves applying a protective layer, often chromate-based, on the zinc coating.

Inspection and Testing

The electro-galvanized coils undergo inspection and testing to ensure they meet specified standards. This may include visual inspection, thickness measurement of the zinc coating, and other quality control measures.

Post-Treatment (Optional)

Depending on the application, electro-galvanized coils may undergo additional post-treatment processes, such as oiling or applying other coatings.

Cutting and Packaging

The final step involves cutting the electro-galvanized coils to the desired sizes and packaging them for shipment. These coils are often delivered to manufacturers for use in various applications, such as automotive parts, appliances, or construction materials.

It’s important to note that the electro-galvanizing process provides a thinner coating compared to hot-dip galvanizing, making electro-galvanized steel suitable for applications where a thinner and more aesthetically pleasing coating is desired. Manufacturers may tailor the process parameters based on the specific requirements of the end-users and industry standards.