Sherardizing

Sherardizing is a process for the surface treatment of metallic workpieces that is often used to improve their corrosion resistance. In this process, the workpieces are placed in a mixture of zinc powder and zinc oxide powder and cemented at a high temperature in a special oven.

During the sherardizing process, zinc atoms diffuse into the surface of the workpiece and form a thin layer of zinc alloys, particularly zinc-iron alloys. This layer provides effective protection against corrosion as zinc has a higher electrode potential difference compared to iron, meaning it is sacrificial and oxidizes before the underlying iron.

The thickness of the sherardizing layer can vary depending on the application, with thinner layers being used for decorative purposes and thicker layers for applications with higher corrosion protection requirements. Once the Sherardizing process is complete, the workpieces can be subjected to further treatments, such as passivation, to further improve corrosion resistance.

Sherardizing coatings are used in a variety of applications, including structural steel, machine parts, fasteners and more. They provide low-cost and effective protection against corrosion, contributing to the longevity and reliability of metallic components.