Zinc-based phosphating liquid is a four-in-one phosphating liquid. It is generally used as a treatment agent before metal spraying to enhance the adhesion of the paint film and increase the life of the metal.
Zinc-based phosphating solution. Phosphating is one of the important methods for preventing corrosion of metal materials. Its purpose is to provide anti-corrosion protection to the base metal, to be used as a primer before spray painting, and to improve the adhesion of the coating layer. Strength and anti-corrosion capabilities and anti-friction and lubrication effects in metal processing.
Phosphating is one of the important methods to prevent corrosion of metal materials. Its purpose is to provide anti-corrosion protection to the base metal, to be used as a primer before painting, to improve the adhesion and anti-corrosion ability of the coating layer and It plays the role of friction reduction and lubrication in metal processing. Phosphating is a commonly used pre-treatment technology, and in principle it should be a chemical conversion coating treatment. The main application in engineering is phosphating the surface of steel parts, but non-ferrous metals such as aluminum and zinc can also be phosphated.
The main components of the phosphating solution are dihydrogen phosphate, such as Zn(H2PO4)2, as well as an appropriate amount of free phosphoric acid and accelerator. The accelerator mainly plays the role of lowering the phosphating temperature and accelerating the phosphating speed. The most commonly used oxidants as chemical accelerators include NO3-, NO2-, CIO3-, H2O2, etc. Phosphating is a process in which metal reacts with dilute phosphoric acid or acid phosphate to form a phosphate protective film. Phosphating liquids are mainly divided into six categories according to the phosphating film-forming system: zinc series, zinc-calcium series, zinc-manganese series, manganese series, iron series, and amorphous phase iron series.
The main components of zinc phosphating bath liquid are: Zn2+, H2PO3-, NO3-, H3PO4, accelerator, etc. The main composition of the formed phosphating film (steel parts): Zn3(po4)2·4H2O, Zn2Fe(PO4)2·4H2O. The phosphating grains are dendritic, needle-shaped, and have many pores. It is widely used in priming before painting, anti-corrosion and cold working anti-friction lubrication. According to the phosphating treatment temperature, it can be divided into four categories: normal temperature, low temperature, medium temperature and high temperature. Phosphating at room temperature means phosphating without heating. The general processing temperature of low-temperature phosphating is 30~45℃. Medium temperature phosphating is generally 60~70℃. High temperature phosphating is generally greater than 80℃. The temperature classification method itself is not strict. Sometimes there are sub-medium temperature and sub-high temperature methods, depending on everyone's wishes, but generally the above-mentioned classification method is followed.