2nd step of Cleaning steel to prepare for the hot-dip galvanized coating Pickling Next the steel is “pickled” in a dilute solution of either hydrochloric or sulfuric acid (Figure 4), which removes oxides and mill scale. Once all oxidation has been removed from the steel, it is again rinsed with water and sent to the final step of the surface preparation.

- Jan 10, 2019-

2nd step of Cleaning steel to prepare for the hot-dip galvanized coating

Pickling

Next the steel is “pickled” in a dilute solution of either hydrochloric or sulfuric acid (Figure 4), which removes oxides and mill scale. Once all oxidation has been removed from the steel, it is again rinsed with water and sent to the final step of the surface preparation.


Previous:step of Cleaning steel to prepare for the hot-dip galvanized coating Fluxing Finally, the steel is dipped in the flux. The purpose of the flux is to clean the steel of all oxidation developed since the pickling of the steel and to create a protective coating to prevent any oxidation before entering the galvanizing kettle. One type of flux is contained in a separate tank, is slightly acidic, and contains a combination of zinc chloride and ammonium chloride. Another type of flux, top flux, floats on top of the liquid zinc in the galvanizing kettle, but serves the same purpose.
Next:1st step of Cleaning steel to prepare for the hot-dip galvanized coating Degreasing/Caustic Cleaning First the steel is immersed in an acid degreasing bath or caustic solution to remove organic contaminants such as dirt, oil, and grease from the surface of the steel. After degreasing the steel is rinsed with water.