How does electrogalvanizing deposit zinc on steel?

Electrogalvanizing, also known as zinc plating, is an electrolytic process used to apply a controlled, thin coating of zinc onto steel. Unlike hot-dip galvanizing, which involves immersing steel in molten zinc, electrogalvanizing occurs without heat.4123

The process typically takes place in a series of electrolytic cells. The steel strip acts as the cathode and is connected to the negative side of a direct current source. As the steel passes through an electrolyte bath—usually an acidic solution of zinc sulfate or zinc chloride—zinc cations (positively charged atoms) are present in the solution.2

When the electric current is applied, these zinc cations are converted into neutral zinc atoms, which then deposit onto the surface of the steel. The electrolyte bath is replenished with zinc either by dissolving zinc anodes or by continuously adding zinc compounds to the solution. This method allows for precise control over the coating thickness and is often used when thinner, highly uniform coatings are required for applications such as automotive steel.24