Galvanized Steel

Galvanizing process

Galvanizing refers to the process of coating a layer of zinc on the metal surface to enhance its corrosion resistance. The following are the main processes of the galvanizing process:

1. Raw material inspection: Check the quality of the materials to be galvanized to ensure that they meet the process requirements.

2. Pickling: Use acid to remove the iron oxide scale and other impurities on the surface of the steel parts.

3. Cleaning: After pickling, the steel parts are thoroughly cleaned to remove residual acid and other contaminants.

4. Zinc-assisting: Apply a layer of solvent containing zinc chloride or a mixture of ammonium chloride and zinc chloride to the surface of the cleaned steel parts to prevent the steel parts from oxidizing again.

5. Drying: Put the steel parts coated with solvent into the drying oven for better subsequent galvanizing process.

6. Galvanizing: Immerse the dried steel parts in molten zinc liquid to make the zinc layer evenly adhere to the surface of the steel parts.

7. Cooling: After galvanizing, the steel parts are quickly cooled to fix the structure of the zinc layer.

8. Passivation: Form a protective film on the surface of the steel to prevent the zinc layer from being further oxidized.

9. Cleaning: Finally, clean the steel to remove any residual material on the surface.

10. Finished product inspection: Perform a final quality inspection on the galvanized steel to ensure that the product meets the standards.

11. Inspection and packaging: Pack qualified products and prepare them for delivery. The above is the basic process of the galvanizing process. It should be noted that different galvanizing processes may have some differences in details, but the overall process is similar.

Electrogalvanized steel

1. Input process: Equipment at the entrance of the electroplating line includes reel take-up, shearing M/C, welding M/C, winder and tension leveler. The reel conveys the stacked or cold rolled steel materials to the shearing machine, which cuts and connects the materials ready for jointing. Then comes welding.

2. Pre-treatment process: The electrolytic cleaning line consists of electrolytic tank, pickling tank and rinsing tank, which are used to remove contaminants and oxide film on the surface of steel before electroplating.

3. Electrogalvanizing: The CAROSEL method, like other electrogalvanizing methods, involves electroplating one side at a time through a conductor roller. The process produces double-sided single-sided, differentially coated plates. There are also horizontal types, in which both sides of the plate are electroplated simultaneously to produce double-sided coated plates.

4. Phosphate film coating: A phosphate film is applied to the surface of the zinc layer by chemical or electrochemical reaction. The film is intended to provide temporary corrosion protection and produce a safe paintable substrate.

5. Anti-fingerprint treatment: organic, inorganic or organic-inorganic hybrid film is applied to the surface of the steel plate to supplement its corrosion resistance and enhance the required properties such as anti-fingerprint marking and processability.

6. Output process: The exit point of the production line includes output reel, tension reel and automatic packaging line to protect the product after winding.