Brief introduction of Galvanized Steel Coil spangle

1. The presence or absence of general Galvanized Steel Coil spangles/normal spangles is related to the zinc bath’s lead (Pb) content. If the lead content is high, spangles will occur. Low-lead or lead-free, it is not easy to produce spangles. The size of the spangle is related to the cadmium, antimony, tin, and other elements in the zinc tank, as well as the line speed, air knife, and air volume.
2. Fine spangles, as soon as the steel plate leaves the zinc tank before the zinc layer is solidified, spray fine zinc powder on the surface of the zinc layer to refine the zinc crystals to obtain fine spangles. This process generally contains lead in the zinc tank, but a “spangle refinement equipment” is installed above the zinc tank to blow zinc powder to refine the spangle.
3. Another process of spangle-free is to control the lead content in the zinc tank to be lead-free or low-lead, and then use nitrogen blowing to control the thickness of the coating so that the spangle-free surface can be obtained without the use of “spangle refinement equipment.”