After this phase lasting about two hours, the material removed from the tank and allowed to drain, is then immersed in water for a rinse and then proceeds with immersion in pickling tanks, composed of hydrochloric acid and water (HCL-H2O ). This step can last from two to four hours and is the most important operation where the surface of the steel product is freed from oxides, rust and residual calamine from the translation and rolling processes.
After a further washing in water, we proceed with the last procedure: flushing. By immersing the material in a solution composed of zinc salts and ammonium salts at about 50 °, a uniform film is formed that prevents oxidation until the moment of immersion in the molten zinc and improves the zinc-iron reaction.