Before anti-corrosion treatment, the sheet metal parts must first be thoroughly derusted and cleaned. This can be achieved by mechanical grinding, pickling or alkali washing to remove rust, oil and other impurities from the surface.
Phosphating treatment is to immerse the sheet metal in a solution containing chemical substances such as phosphates to form a phosphating film on the surface of the sheet metal through chemical reactions. This phosphate film can significantly improve the corrosion resistance of sheet metal and enhance the bonding between the coating and the substrate.
Selecting the right primer is key to corrosion protection. Commonly used primers include epoxy zinc-rich primer, epoxy iron red primer, etc. These primers have good rust protection and adhesion, providing long-term corrosion protection for sheet metal.
Over the primer, intermediate and topcoats can be applied to further enhance corrosion protection. The middle layer usually adopts epoxy mica iron oxide coating, etc., which has excellent corrosion resistance, weather resistance and sealing properties. For the topcoat, you can choose high-performance coatings such as acrylic polyurethane and fluorocarbon to improve the weather resistance and aesthetics of the sheet metal.
Electrophoretic coating is a highly effective anti-corrosion treatment method. It uses the effect of electric field to make the paint particles deposit on the surface of sheet metal in a direction under the action of electric field force, forming a uniform and dense protective coating. This coating has excellent anti-rust properties and adhesion, and can effectively isolate sheet metal parts from external corrosive media.
Hot-dip galvanizing is the process of immersing sheet metal into molten zinc liquid to allow the zinc to metallurgically bond with the surface of the sheet metal to form a solid zinc layer. This zinc layer has excellent corrosion resistance and can effectively prevent sheet metal parts from rusting in a humid environment.
Passivation treatment, sandblasting, anodizing and other methods can also be used to improve the corrosion resistance of sheet metal parts. These methods have their own characteristics and can be selected according to specific application environment and requirements.
Anti-corrosion treatment of household appliances (special-shaped) sheet metal parts requires comprehensive consideration of multiple factors, including the material of the sheet metal parts, application environment, cost budget, etc. By selecting the appropriate anti-corrosion treatment method, the corrosion resistance of sheet metal parts can be significantly improved, their service life can be extended, and the stable operation of home appliances can be ensured.
