Product preparation procedures prior to hot dip galvanizing:
After dipping the steel into the melted at 4500 C zinc, several layers of iron-zinc alloys are formed which are harder than the base steel and protect from both physical and chemical external factors.
The reaction speed is parabolic, initially high, when the basic coat thickness is being formed – usually the first 4-5 minutes. The speed then decreases and the coating thickness does not increase significantly, even if the product remains in molten zinc. Internal plant conditions do not affect the quality of zinc coating.
The basic hot dip galvanizing specification is defined in the standard EN ISO 1461 “Coatings by Hot Dip Galvanizing of Finished Cast Iron and Steel Products – Technical Requirements and Testing Methods”.