Phosphating is a chemical and electrochemical reaction to form a phosphate chemical conversion film. The phosphate conversion film formed is called a phosphate film. The purpose of phosphating is mainly to provide protection to the base metal, to prevent the metal from being corroded to a certain extent; to base the paint before painting, to improve the adhesion and corrosion resistance of the paint layer; to reduce friction in the metal cold working process Lubrication use
Phosphating process 1. Degreasing (chemical: degreasing agent or degreaser).
Good or bad generally has no oil on the surface as the standard. 2. Filtration of clean water. 3. Derusting (chemical: hydrochloric acid) must not leave rust on the surface. If there is no rust, it is best not to be too acidic, neutral (chemical: soda ash) PH value is 11-12, clear water filtration 6, table adjustment seven, phosphating eight, water filtration
The saponification reaction is a base-catalyzed ester hydrolysis reaction, especially hydrolysis of oils and fats.
