The difference between electro-galvanizing and hot-dip galvanizing
1. Differences in zinc layer thickness:
The cold electroplated zinc layer is extremely thin, usually only 3-15 microns;
The hot-dip galvanizing layer is very thick. The minimum thickness allowed by the market is 45 microns, and the maximum thickness can be more than 300 microns.
2. Service life:
Electroplated products have a short service life due to their thin zinc layer. In the short term, if there is insufficient pickling and the air is humid, dezincification and oxidation will occur within a few weeks in severe cases.
Depending on the thickness of the zinc layer, hot-dip products may become severely oxidized in the next few years or decades.
3. Hot-dip galvanizing has the following advantages compared with electro-galvanizing:
(1) It can generate a thicker coating, and has both a pure zinc layer and an iron-zinc alloy layer, so the corrosion resistance is better;
(2) The production efficiency of hot-dip galvanizing is particularly high; the time the parts stay in the hot-dip galvanizing tank generally does not exceed 1 minute;
(3) Compared with electroplating, hot-dip galvanizing has lower production costs and has less impact on the environment than electroplating;
(4) The degree of automation is high when plating profiles such as plates, strips, wires, and tubes.
4. Hot-dip galvanizing has national standards, while cold-dip galvanizing is not advocated by the country because it pollutes a lot.