The core technology of the hot-dip galvanizing equipment for low-carbon steel wire involves two key aspects: gas-based reduction treatment to condition the wire surface, and cooling the wire from 780°C to a range of 450°C–500°C before it enters the zinc bath.
The reduction annealing process utilizes a tubular muffle furnace into which a protective atmosphere-generated by the decomposition of liquid nitrogen-is introduced, allowing the wire to undergo annealing and reduction within this protective environment. The primary chemical reaction occurring inside the furnace tube at high temperatures is Fe₂O₃ + 3H₂ → 2Fe + 3H₂O, with the resulting water vapor being exhausted from the high-temperature tube.
In the hot-dip galvanizing process, the wire-maintained at a temperature of 450°C–500°C-enters the zinc bath under sealed conditions and immediately undergoes an alloying reaction upon contact with the molten zinc.
The complete technological workflow consists of wire pay-off, electrolytic degreasing, hot water rinsing, reduction annealing, controlled cooling, hot-dip galvanizing, cooling, and take-up.