Hot-Dip Galvanizing & Electro-Galvanizing for Cable Trays

Hot-Dip Galvanizing (HDG)

Zinc exhibits excellent corrosion resistance under atmospheric conditions. Galvanizing is a cathodic protection method for polar metals, where zinc acts as a sacrificial anode. Its corrosion resistance lifespan depends on the zinc coating thickness and corrosion rate. The zinc layer thickness of hot-dip galvanizing is generally above 65 μm (455 g/m²). A zinc-iron alloy layer forms at the interface between zinc and iron, enhancing the adhesion of the zinc coating. Atmospheric exposure tests on hot-dip galvanized layers under various environmental conditions have been conducted overseas. Test results indicate that hot-dip galvanizing can meet the service life requirements of steel cable trays.

Steel hot-dip Galvanized cable trays are widely used domestically and internationally due to their superior corrosion resistance and high cost-performance ratio.

For components with thin walls or large slenderness ratios, deformation and other issues are likely to occur during hot-dip galvanizing. Such factors must be considered in the structural design of cable trays and the galvanizing process.

Hot-Dip Galvanized Cable Tray Production

Electro-Galvanizing

Compared with hot-dip galvanizing, electro-galvanizing features a simpler process and lower cost, with no special requirements for the cable tray structure. As introduced by hot-dip galvanized cable tray manufacturers, the protective performance of electro-galvanizing can be significantly improved through passivation treatment. The electro-galvanized layer thickness is generally around 12 μm. Therefore, it is not suitable for applications requiring a long corrosion resistance lifespan.

China has established ministerial standards for electro-galvanizing, which clearly specify the selection of electroplating layer types, coating thickness, adhesion strength, and corrosion resistance tests. These standards vary in applicable objects and content requirements. Currently, there are numerous manufacturers producing electro-galvanized cable trays in China, and their reference and application of the aforementioned technical standards also differ.