The pickling and phosphatizing process is a chemical and electrochemical reaction that forms a phosphate conversion film. The resulting phosphate conversion film is known as the phosphatizing film. The main purpose of phosphatizing is to: provide protection to the base metal, to some extent preventing corrosion of the metal; to serve as a primer before painting, enhancing the adhesion and corrosion resistance of the paint film; and to act as a lubricant in the cold working process of metals.