Hot dip galvanizing industrial process of steel pipe

• from：迅xunzhuoweb
• admin：admin123
• date： 2022-04-29

1. Surface pretreatment process section. It includes hot water cleaning of steel pipe, degreasing treatment, water cleaning, pickling treatment,
water storage and plating agent treatment and drying process. Hot water cleaning is to remove metal chips, dust, rust and cutting iron chips on
 the surface of the steel pipe. During the treatment, the steel pipe is immersed in a hot water tank for cleaning, and at the same time, the steel
pipe is preheated to strengthen the effect of the next degreasing and pickling process. The cleaned steel pipe is cleaned in a chemical degreasing
tank in order to remove grease on the surface. After degreasing, the steel pipe is cleaned with hot water again to remove the residual alkaline
degreasing solution and degreased sediment. In order to remove rust and iron oxide on the surface of the steel tube, the steel tube is pickled in
an acid pickling tank, usually in an acid washing solution with corrosion inhibitor. After pickling, the steel pipe should be cleaned with water to
remove pickling residual solution and sediment. After pickling, the steel pipe is immersed in weak acid cold water tank for storage, and prepared
for the next dip - aid plating process. The main function of dip coating aid is to remove the oxide and ferric salt on the surface of steel pipe so
as to ensure that the surface of steel pipe is kept clean and not oxidized again before dipping zinc.

2. Galvanizing process section. The galvanizing process section includes the hot dip zinc treatment of steel tubes. The steel tube dipped with
plating aid is dried in a drying furnace and preheated to about 200 degrees. Preheating steel tube can reduce the heat consumption of zinc
pot, reduce the intensity of zinc pot heating, so as to prolong the service life of zinc pot, improve the working conditions. The baked steel
pipe is sent into the zinc pot by the galvanizing machine and then removed from the zinc pot. The surface of the steel pipe is soaked with
liquid zinc layer. After zinc dipping, steam and compressed air are immediately used to spray the coating externally and internally, in order
to remove excessive zinc on the surface and make the coating surface uniform and smooth.

3. Post-plating process section. The post-plating treatment process includes the process of zinc dipping steel pipe leaving the zinc pot until
it is cooled to room temperature. It includes the air cooling, water cooling, drying, passivation and other processes after the pipe is sprayed
outside and inside. After spraying treatment, the steel tube can be cooled quickly and the growth of fe-Zn alloy layer can be stopped.
Galvanized steel pipe can be passivated as required.

4. Post-processing technology section. The post-processing technology of steel pipe refers to the procedures such as inspection, wire turning,
straightening, printing, weighing, strapping and packaging of steel pipe after hot dip galvanizing.