Galvanized steel sheet can effectively prevent steel corrosion and prolong service life. Galvanized steel sheet (thickness 0.4~1.2mm) is also called galvanized iron sheet, commonly known as white iron sheet. Galvanized sheets are widely used in construction, vehicles, household appliances, daily necessities and other industries. Factors such as improper use of galvanized sheet or careless protection will cause many problems.
So, what is the reason for the peeling of the zinc layer of the galvanized sheet? Let us find out the main reasons for the zinc layer of galvanized sheet to fall off are: surface oxidation, silicon compounds, cold-rolled latex too dirty, too high oxidizing atmosphere, high protective gas dew point in the NOF part, unreasonable air-fuel ratio, low hydrogen flow, and oxygen Penetrating into the furnace, the temperature of strip steel entering the pot is low, the furnace pressure in the RWP part is low, the furnace door suction is low, the furnace temperature in the NOF part is low, the grease does not evaporate, the liquid level of the aluminum content zinc pot is low, and the unit speed is too fast , The reduction amount is insufficient, the residence time of the zinc liquid is too short and the coating is too thick.
Galvanized steel sheet is a welded steel sheet with a hot-dip galvanized or electro-galvanized layer on the surface, which is usually widely used in construction, household appliances, vehicles, containers, container manufacturing and electromechanical industries. High-quality galvanized steel sheets have high requirements for galvanizing and mechanical properties.
The amount of galvanized sheet
Standard value of galvanized sheet: galvanized layer is a common and effective method to express the thickness of zinc layer of galvanized sheet. The two sides with the same galvanizing amount on both sides (that is, the galvanizing with the same thickness), and the two sides with different galvanizing amounts (that is, the galvanizing with different thicknesses) on both sides. The unit of zinc plating is g/m2 (grams/square).
Mechanical properties of galvanized steel sheet
1. Tensile test: Generally speaking, only galvanized sheets used for structure, stretching and deep drawing have tensile properties.
2. Bending test: It is the main item to measure the process performance of thin plates. However, the national standard requirements of various galvanized sheets are inconsistent. It is generally required that after the galvanized sheet is bent 180 degrees, there should be no zinc layer on its outer surface, and there should be no cracks or breaks in the board base.
