A worker charges for easy pickling, put 10% of hydrochloric acid, pickles for about 30 minutes, and keep the temperature at 28℃. Totally remove the iron oxide of material surface by doing the second pickling at the room temperature, maintaining 7~10% of hydrochloric acid. The working time is 5 minutes.
Wash the product after pickling with the water.
Defective goods are done pickling after inspection.
Fluxing is for easy coating by forming a film on steel surface. In order to make the liquid, keep 30% of zinc chloride + ammonium chloride, and keep the temperature at 89~90℃
Drying work preheats and dries in order not to burst up. The preheat temperature of material keeps at 200℃
도금작업은 아연용탕 온도를 450℃ 정도를 유지하며 작업을 행한다.
작업은 침적시간을 90초 정도에서 산화재를 제거하여 천천히 끌어올린다.
Cool the coated products with the water in order to prevent the surface oxidation and expansion restraint of alloyed layer.
The continuous increase of labor cost makes the total costs in other coating methods to be increased. So the economic feasibility of Hot Dip Galvanizing has increased much.
The hot dip galvanizing has longer life than other methodsand no need of repair. When we consider the repair time and cost, this method is economical because of saving the repair costs and labor costs.