There are many kinds of Dacrol coating, but the basic composition of the coating can be summarized as follows:

1. Metal: composed of zinc, aluminum and other materials, mainly ultrafine scaly zinc and ultrafine scaly aluminum.

2. Solvent: inert organic solvent, such as ethylene glycol, etc.

3. Inorganic acid components: such as chromic acid, etc.

4. Special organic matter: it is a viscous dispersive component of the coating solution, and its main component is white powder of cellulose.

The protective effect of Dacromembrane on steel matrix can be summarized as follows:

1. Barrier effect: due to lamellar overlap of sheet zinc and aluminum, the process of water, oxygen and other corrosive media reaching the matrix is blocked, which can play an isolated shielding role.

2. Passivation: in the process of dacro treatment, chromic acid and zinc, aluminum powder and the base metal chemical reaction, the formation of dense passivation film, this passivation film has good corrosion resistance.

3. Cathodic protection: The most important protective effect of zn-Al-Cr coating is the same as that of zinc coating, which is to carry out cathodic protection on the matrix.