◆ Galvanized vs Galvalume

The difference between galvanized steel sheet and galvalume steel sheet is mainly the difference in coating.

A layer of zinc material is evenly distributed on the surface of the galvanized steel sheet, which acts as an anodic protection for the base material, that is to say, the alternative corrosion of the zinc material protects the use of the base material, and only when the zinc is completely corroded can it damage the inside base material.

The surface coating of the galvalume steel sheet is composed of 55% aluminum, 43.5% zinc and a small amount of other elements. Microscopically, the surface of the galvalume coating is a honeycomb structure, and the "honeycomb" composed of aluminum contains zinc.

In this case, although the galvalume coating also plays the role of anodic protection, on the one hand, due to the reduction of zinc content, on the other hand, the effect of anodic protection is greatly reduced because the zinc material is wrapped in aluminum and is not easy to be electrolyzed.

Therefore, once the galvalume steel sheet is cut, it will rust soon when the cut edge basically loses its protection, so the galvalume sheet should be cut as little as possible. Once cut, anti-rust paint or zinc-rich paint should be used to protect the edges to prolong the service life of the galvalume steel sheet.

◆ Characteristic

Characteristics of galvalume steel sheet: