What are the characteristics of galvanized steel sheet for corrosion

When galvanized steel sheet is exposed to the air, dry etching, wet cold etching and wet etching are the key conditions.

The dry etching of galvanized steel sheet refers to the etching of steel surface in ambient air with air humidity less than 30%, which does not produce a continuous electrolyte water film. Under such circumstances, the corrosion rate of steel

Quite slow. However, there are few standards for such natural environment.

The wet cold etching of galvanized steel sheet refers to the etching of steel in ambient air with air humidity of more than 30% and less than 100%. Under such circumstances, there is dust on the surface of steel, and there are micro particles in the rust layer

The pores and gaps cause the microscope to absorb and produce shrinking water that can't be seen by human eyes. The principle of galvanic cell is generated under shrinking water, and the etching rate is relatively fast.

The wet etching of galvanized steel sheet refers to the etching of galvanized steel sheet when there is solidified shrinkage water visible to the human eye on the surface in the humid and cold ambient air where the air humidity exceeds 100%. In such a case

The shrinkage water on the steel surface is too thick, which makes the diffusion rate of oxygen to the steel surface is relatively slow after oxygen melting, reducing the etching rate. In fact, the corrosion of steel is closely related to the shrinkage water of the surface layer between the two, especially due to

Water, and co2 is dissolved in the water, which makes iron produce weak electrolyte and a series of weak electrolyte reactions.

The co2 in the gas is continuously dissolved in the water, and the reflection is also constantly carried out. Because the key product reflected is bright red, the material after iron air oxidation is generally called "red rust". Red rust is sparse

Loose, very easy to melt, and unable to maintain the steel surface from re etching, it promotes the steel etching to be carried out until it is completely etched, which is the characteristic of steel. Because of this, the steel must be coated with

Thickness of other metal materials or metal material protective layer to reasonably avoid corrosion of steel.