The metal surface painting process is an important metal corrosion protection method. The good paint coating protection layer is continuous and intact, and the combination is good, which can become a barrier to inhibit the intrusion of corrosive media. However, since corrosion is an irreversible spontaneous process, even if it is a good paint coating and retaining layer, it is difficult to protect the metal from corrosion, especially when the metal surface paint coating layer is poorly bonded, damaged, or has pinholes, drums. Defects such as bubbles, cracks, and shedding, the protective effect of the spray coating will be greatly reduced, and even the consequences of increased metal corrosion will be caused. Therefore, it is necessary to carefully analyze the metal corrosion factors of spray paint and take effective countermeasures.
In general, corrosion of metals is the result of a combination of factors, some of which play an important role in the corrosion process. The metal surface is painted to form a coating protective layer, and the region where the metal is corroded is in the interface region between the painted paint film and the metal surface, and continuously erodes and expands deep into the metal substrate.
Innovation in metal painting on spray painting process
If the metal surface paint coating layer can effectively isolate water, oxygen and electrons, stray ions, etc., it can greatly reduce or avoid the corrosion of the coated metal. If the isolation effect is not good, the coating layer is applied to the metal. The protection against corrosion and corrosion is not good. Production practice shows that the penetration of water by the spray coating protective layer seriously hinders the adhesion of the metal paint coating surface, and the oxygen permeability largely hinders the corrosion performance of the metal. There are many forms of corrosion of paint-coated metals, but the root cause, corrosion, is closely related to chemical and electrochemical effects.
The anti-corrosion and anti-corrosion properties of the paint-coated metal can be effectively improved by the pre-treatment and surface treatment processes of the metal surface before painting and painting. The production practice confirms the pros and cons of the metal coating of the paint coating and the quality of the pre-treatment of the substrate before coating. The effective degreasing, derusting or spraying of the metal (especially the casting) before the surface coating is carried out. Sand shot peening can cause purification of the activated surface, ensuring a good joint effect between the painted paint film and the base metal, which is very beneficial for improving the corrosion resistance of the painted metal.