Galvanized Steel Coil

Galvanized steel coil, dip a sheet steel plate into a melted zinc tank, so that the surface adhesion of a zinc sheet steel. It is mainly produced by continuous galvanizing process, that is, the rolled steel plate is continuously dipped in the melting zinc bath to make galvanized steel plate; Alloyed galvanized steel plate. This steel plate is also made by hot dipping, but immediately after it is out of the groove, it is heated to about 500℃ to create an alloy coating of zinc and iron. This galvanized coil hasgood coating tightness and weldability.

(1) Normal zinc coating spangle coating in the normal solidification process, zinc grains grow freely to form a coating with obvious zinc flower morphology.

(2) In the process of zinc solidification, zinc grains are artificially limited to form minimized spangle coating, minimized spangle coating.

(3) Zincfree coating spanglefree obtained by adjusting the chemical composition of the plating solution, does not have visually visible zinc flower morphology, uniform surface coating.

(4) Heat treatment of the steel strip after zinc bath, so that the entire coating generated zinc and iron alloy layer, this coating appearance is dark gray, no metal luster, easy to powder in the violent molding process, suitable for general cleaning, A coating that can be applied directly without further treatment.

(5) Differential coating on both sides of galvanized steel plate, the coating with different zinc layer weight is required.

(6) Skin pass Skin Pass is a cold rolling process of galvanized steel with small deformation for one or more of the following purposes. Improve the surface appearance of galvanized steel plate or suitable for decorative coating; To temporarily minimize the phenomenon of slip lines (Luders lines) or creases that occur when the finished product is not processed.

The main reasons for the loss of zinc layer are: surface oxidation, silicon compounds, cold binding emulsion is too dirty, NOF section oxidation atmosphere and protective gas dew point is toohigh, air fuel ratio is unreasonable, hydrogen flow rate is low, furnace aerobic infiltration, strip into the pot temperature is low, RWP section furnace pressure is low and door suction, NOF section furnace temperature is low, Grease evaporation is not enough, zinc pot aluminum content is low, unit speed is too fast, insufficient reduction, zinc liquid residence time is too short, coating thickness.