Why does galvanized square pipe turn white?

The whitening of galvanized square pipes is due to the oxidation of the zinc layer, forming white powdery zinc oxide. This oxidation is inevitable because the alloy properties of the zinc layer determine that it is more susceptible to oxidation reactions in the atmosphere.

Specifically, zinc is an amphoteric metal that is relatively reactive and is more susceptible to corrosion in generally humid environments. Even if it can be dried in time after rain, galvanized products may still be greatly affected, because slight corrosion of the galvanized layer will cause large color differences, affecting the appearan

ce of the product. In addition, if the zinc layer is not manufactured or handled correctly during the manufacturing process, or if the zinc layer is exposed to humid air for too long, the oxidation process will be accelerated, making the galvanized square pipe white.

In order to prevent galvanized square pipes from turning white, a series of measures need to be taken.

First of all, when storing galvanized products, they need to be placed in a dry, ventilated, and cool place, away from fire sources and flammable substances.

Secondly, different types of galvanized square pipes should be stacked separately to avoid confusion and contact corrosion. The warehouse should be selected based on geographical conditions. Generally, ordinary closed warehouses are used, that is, warehouses with roof walls, fastened doors and windows, and ventilation devices. In sunny weather, ventilation should be paid attention to, while in humid weather, the warehouse should be kept closed.

In short, to prevent galvanized square pipes from turning white, attention needs to be paid to storage environment, classified storage, protective measures and other aspects to ensure the quality and service life of galvanized products.

Editor: Lucas

Mail: lucas@yangtzesteel.com