What does pickling mean?

The metal surface is exposed to acidic solution, and then phosphate coating is formed by chemical reaction. Pickling is a surface treatment technology, which is often used to prevent corrosion of metal products and improve adhesion. By exposing the metal surface to an acidic solution, a phosphide coating is formed in a chemical reaction. After pickling and phosphating, the metal surface has good corrosion resistance and can protect the metal from oxidation or chemical corrosion.