The hot-dip galvanizing process is a long-term anti-corrosion technology, which is widely used in iron towers, electric power, highway guardrails, and building steel structures. The hot-dip galvanizing process usually consists of pre-treatment, hot-dip galvanizing and post-treatment. Pre-treatment includes degreasing, pickling and derusting, solvent assisted plating, drying and other processes, and post-treatment includes cooling, passivation and plating parts repair. The process flow chart is as follows:

Degreasing-- water washing-- pickling-- water washing-- plating flux-- drying-- hot-dip galvanized parts-- cooling-- passivation-- overhaul


Usually the iron parts are stained with some grease due to the iron parts or the assembly line. For example, oil, butter, paint, etc. Generally speaking, it needs to be dealt with when this situation is found.


Hydrochloric acid pickling is a rust removal process widely used at present. The lower the mass fraction of hydrochloric acid, the longer the pickling time. In addition, the pickling temperature has a greater impact on the pickling time.

Water washing

Water washing is a very important link in hot dip galvanizing. Iron ions are brought into the zinc pot from the surface of iron parts, which leads to excessive zinc ash and zinc slag, so water washing must be careful.

Promotion flux

Promotion flux is an important link. It can not only make up for the shortcomings of the previous several processes, but also activate the surface of steel parts and improve the quality of galvanized. Its quality directly affects the coating and quality, and has a great impact on the cost of zinc consumption.

Hot dip galvanizing process


After the parts were soaked in the promotion flux, the amine liquid was cleaned and put on the drying stove. If the parts were put into the pot too early, the zinc would explode and too late would cause leakage plating.

Hot dipping

The plating parts are immersed in zinc solution and galvanized. In the process of galvanizing, pay attention to the speed and angle of the plating parts’ sinking and lifting, the temperature of zinc solution, the treatment of zinc ash and zinc slag and other matters.


The iron parts are lifted from the zinc pot, and put the parts into the water before the coating on the surface does not become gray as soon as possible .


When the parts need to be stored and transported for a long time, passivation should be carried out to prevent the production of atmospheric corrosion of white rust.


Overhaul is the last procedure of hot-dip galvanizing process. Workers should carefully inspect the surface of the plating parts. There is no leakage, zinc nodding or hanging zinc, and the surface of the parts is not bright, so as to make the final remedy to meet the requirements of customers.

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