one、definition

Galvanized coil is a metal material that enhances its corrosion resistance by coating a layer of zinc on the surface of the steel coil。The galvanizing process mainly includes two types: hot-dip galvanizing and electroplating galvanizing，Among them, hot-dip galvanized coils have high cost-effectiveness、Strong adhesion of zinc layer、Good corrosion resistance and other characteristics，Widely used。

two、Production process

（one）Production of hot-dip galvanized coils

raw material preparation

The raw materials for hot-dip galvanized coils are usually cold-rolled coils or hot-rolled coils。High surface quality of cold-rolled coil，Good dimensional accuracy，Suitable for products with high surface requirements；Hot rolled coils are suitable for the production of thicker galvanized coils。

acid pickling

Before entering the galvanizing tank, the steel coil，Need to go through acid washing process，To remove surface oxide scale and rust。Acid pickling solution usually uses hydrochloric acid or sulfuric acid，Strict control of acid concentration is required during the pickling process、Temperature and pickling time，To ensure surface cleanliness and prevent damage to the substrate。

galvanizing

After pickling, the steel coil enters the molten zinc tank for galvanizing。The temperature of the zinc liquid in the zinc tank is usually450℃about。After immersing the steel coil in zinc solution for a certain period of time，A uniform layer of zinc will form on the surface。The thickness of the zinc layer can be adjusted by controlling the immersion time and the composition of the zinc solution。

Cooling and passivation

Galvanized steel coils need to undergo a cooling process，Usually using air cooling or water cooling。The surface of the cooled steel coil will undergo passivation treatment，To improve its corrosion resistance and surface quality。Passivation treatment usually uses chromate or chromium free passivating agents。

Inspection and packaging

finally，Galvanized coils need to undergo quality inspection，Including the thickness of the zinc layer、SURFACE QUALITY、Testing of adhesion and other aspects。Qualified galvanized coils will be packaged and stored，Waiting for shipment。