As a Sheet Metal CNC Bending Processing Supplier, I would like to share with you what are the anti-corrosion methods for the galvanized layer of sheet metal processing.
(1) Galvanizing (EG) The basic sheet metal processing process of electro galvanizing is: part pre-plating → degreasing → erosion → polishing → galvanizing → dehydrogenation → passivation/dyeing. Electroplating can form a uniform and dense galvanized layer with pure surface, thin oxide film, higher surface activity than phosphating, good flexibility, and high corrosion resistance. The uniformity of coating quality is worse than that of hot-dip galvanizing, but the thickness of coating is not as good as that of hot-dip galvanizing. Because of its high surface quality, it is most suitable for passenger car body exterior panels.
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(2) The sheet metal processing process of hot dip galvanizing (GI/GA) hot dip galvanizing is: pre-plating parts → degreasing → washing → pickling → washing → pressing → water solvent coating → drying → galvanizing → Cooling → straightening → oiling → packaging.
Hot-dip pure zinc (GI): Alxoy, the ZnO film is thick and the thickness varies widely, and the surface chemical activity is lower than that of electro-galvanized; its corrosion resistance is good, and the surface quality is equivalent to that of electro-galvanized.
Hot-dip galvanized iron alloy (GA): Fe in the cold-rolled substrate of GI products diffuses into the zinc layer through the heat treatment process to form a zinc-iron alloy containing about 10% iron, which has relatively good corrosion resistance; alloying treatment makes the coating formed The multi-layer phase structure improves the adhesion of the coating and improves the solderability of the coating. After phosphating, the surface of the coating has better corrosion resistance under the film, but there are common pinhole defects.
(3) Mechanical galvanizing The sheet metal processing process of mechanical galvanizing. The different processes are mainly different in the methods of establishing the base layer and thickening the coating, which can be roughly divided into two types. Our company also has Sheet Metal CNC Stamping Processing on sale, welcome to contact us.