Everyone knows that during the manufacturing process of stainless steel screens, a passivation film is formed on its surface, and it exists in the form of more stable oxides in nature. However, if the surface passivation film is damaged, the metal surface exposed in the corrosive environment is easily susceptible to corrosion. It is the passive corrosion film on the surface of the stainless steel screen. The weak corrosion resistance part forms a pitting reaction due to the self-excitation reaction, generates small pores, and adds chlorine ions to form a strong corrosive solution, which will accelerate the corrosion reaction. The surface will encounter various oil stains or surface scratches.
There is also intergranular corrosion cracking inside the stainless steel screen, which will have a destructive effect on the passivation film on the surface of the stainless steel screen. Therefore, the surface of the stainless steel screen must be regularly cleaned and maintained. At this time, we must treat the surface as smooth and dazzling as those of decorative screens we have seen. Common materials used to clean up the surface of stainless steel screens are: quartz sand, pig iron rust, pig iron pellets, abrasives, and finely divided nut shells.
Soft materials: Soft materials include finely divided kernels and finely divided plastics. They are suitable for processing screens made of copper, tin, zinc, aluminum and some of their alloys. They can also be used to process coatings on screens. Depending on the sprayed material, the surface can be matte or shiny.
Raw rust: Raw rust is more expensive than quartz sand, but has higher processing capacity and longer life. Pig iron dust produces less dust, and the surface quality is relatively uniform after the particle size. Although pig iron scraps are more expensive, they are more economical to use. Pig iron scraps are first used to clean castings and forgings (removing rust / swag and oxide scale), etc. It should not be used to clean stainless steel and non-ferrous metal screens, because the particles of pig iron scraps left on the surface after cleaning are rusted, unless Surfaces are further treated after use.
Quartz sand: The particles of quartz sand used for sandblasting should have the corresponding shape and size. Quartz sand is severely broken during the blasting process. Especially for pneumatic blasting, the pressure used must not exceed 3 atmospheres. The ability of sand to peel off metallic particles from the surface of a part is much smaller than pig iron shavings. When the surface is processed with quartz sand, a lot of dust is generated due to the crushing of the sand. Quartz sand is used only when stainless steel screens should not leave traces of pig iron scraps.