The difference between electro-galvanized and hot-dip galvanized

galvanizedsteel can easily rust or even be completely damaged in air, water or soilAnnual steel loss due to corrosion accounts for about 1/10 of the total steel production, on the other hand, in order to make steel products and parts surface has a special function, while giving its surface decorative appearance, so, generally use galvanizing method to deal with it, the principle:because zinc in the dry air is not easy to change, and in the humid air, the surface can produce a very dense alkali-type zinc carbonate film, this film can effectively protect the interior from corrosionAnd when, for some reason, the coating is damaged and the steel base is exposed to a small size, zinc and the steel substrate form a micro-battery, making the steel substrate become cathode and protectedii, performance characteristics:1, zinc plating layer thick, fine crystallization, uniform and no pores, corrosion resistance is good; Zinc plating layer after the bluntization of chromium acid to form white, color, military green, etc, beautiful and generous, with a certain decorative properties,4, because the zinc plating layer has good ductility, so can be cold punching, rolling, bending and other molding without damaging the coatingthree, application range:with the development of scientific and technological production, electroplating industry involved in more and more extensive fieldsAt present, the application of galvanizing has been throughout the national economy in various production and research sectorsFor example, machine manufacturing, electronics, precision instruments, chemicals, light industry, transportation, weapons, aerospace, atomic energy and so on, in the national economy is of great significancethermal zinc immersion:, overview: in a variety of protective steel substrate coating methods, thermal zinc immersion is a very good one It is in the state of zinc liquid, after a rather complex physical and chemical effect, in steel not only plated a thicker layer of pure zinc, but also the formation of a zinc-iron alloy layer This plating method not only has the corrosion resistance of galvanizing, but also has a zinc-iron alloy layer It also has the strong corrosion resistance that electroplating cannot be compared with Therefore, this plating method is particularly suitable for a variety of strong acid, alkali fog and other strong corrosion environment II, principle: hot galvanizing layer is zinc in high temperature liquid, formed in three steps: 1, iron-based surface is dissolved by zinc liquid zinc-iron alloy layer ; three, performance characteristics: (1) with a thick dense pure zinc layer covered on the steel surface, it can avoid the steel substrate and any corrosion solution contact, protect the steel substrate from corrosion In the general atmosphere, the surface of the zinc layer forms a very thin and dense zinc oxide layer surface, it is difficult to dissolve in water, so the steel substrate plays a certain protective role If zinc oxide and other components in the atmosphere produce insoluble zinc salts, the corrosion resistance is more ideal (2) has iron-zinc alloy layer, combined with denseness, in the oceanic salt spray atmosphere and industrial atmosphere performance of corrosion resistance, (3) due to the combination of strong, zinc-iron mutual, has a strong wear resistance, (4) because of the good ductility of zinc, its alloy layer and steel base adhere to a solid Therefore, hot plating parts can be cold-punched, rolled, wired, bending and other molding without damaging the coating, (5) steel structure after hot galvanizing, equivalent to a annealing treatment, can effectively improve the mechanical performance of the steel substrate, eliminate the stress of steel mold welding, is conducive to turning steel structure (6) after hot galvanizing the surface of the piece bright and beautiful (7) pure zinc layer is the most plastic layer of galvanizing layer of hot galvanizing, its properties are basically close to pure zinc, with ductility, so it is flexible four, application range: the application of hot galvanizing with the development of industry and agriculture has also expanded accordingly Therefore, hot galvanized products in industry (such as chemical equipment, petroleum processing, marine exploration, metal structure, power transmission, shipbuilding, etc.), agriculture (e.g irrigation, housing), construction (e.g water and gas transmission, wire casing, scaffolding, housing, etc.), bridges, transportation, etc., has been adopted in recent years Because of the characteristics of hot galvanizing products with beautiful appearance and good corrosion resistance, the application range is more and more extensive "