Process of hot-dip galvanizing

How do we execute hot-dip galvanization?
Zinc plant performs hot-dip galvanization services pursuant to standard EN ISO 14 713 – hot-dip galvanization.

Pursuant to the above-mentioned, all steel elements whose dimensions match the tubs and which are technologically ready for hot-dip galvanization can be galvanized.

  Dimensions (max)                          13,8m x 1,7m x 3,2m
  Weight (max)                                  10000kg
Technology envisages three stages of structure preparation:
  1. Creation of holes for release of air from hollow closed parts and pockets,  
  2. Surface without paint, i.e. remains of other surface protection and
  3. Cleaned and nonporous welds.

Technological procedure includes four main stages

Hanging elements
In the first stage, the elements are hanged on special beams with wires or chains.
The beams on which the elements are hung are transported
with cranes during whole procedure.


Chemical cleaning / previous preparation of surface
hemijski-tretmanThe initial stage is degreasing (elimination of grease, oil, emulsion…) in acidic degreaser, which is followed by pickling (removal of rust) in  hydrochloric acid. When the metal elements are cleaned, we rinse them in water once again and dip into a tub with flux which secures good metallurgical reaction between zinc and steel. After that,  drying in the drying chamber follows.

Hot-dip galvanization in zinc coulee and passivation
Prepared elements are dipped in zinc coulee. During this procedure, metallurgical bonding of zinc and iron occurs. If needed, we cool the elements in water and passivize them in inorganic solution, in case of a special request of the buyer.  


Separation, cleaning and packaging

poc-elem-07-copyThe last stage includes separation, cleaning of zinc drops, zinc ash, additional processing of non-galvanized surfaces pursuant to standard EN ISO 1461 and packing. The product is measured at the end and stored at terminal, where it awaits dispatching.