1.What is the core range of zinc liquid temperature?
Standard range: usually controlled at 430-460℃, adjusted according to steel thickness, zinc liquid composition (such as aluminum content) and process requirements.
Temperature influence:
Temperature is too low: zinc liquid has poor fluidity, the coating thickness is uneven, and defects such as leakage and nodules are prone to occur.
Temperature is too high: zinc liquid oxidation intensifies, zinc slag generation increases, and the steel matrix is excessively dissolved, resulting in brittle coating and excessive thickness.
2.How to control temperature uniformity?
Zinc pot heating method: When using electric heating, gas heating or induction heating, it is necessary to ensure that the temperature difference in each area of the zinc pot is ≤5-10℃.
Temperature measurement point arrangement: Set thermocouples at different depths and positions (such as center and edge) of the zinc pot to monitor temperature fluctuations in real time.
3.What is the purpose of preheating?
Remove moisture from the workpiece surface to avoid splashing of zinc liquid when entering the zinc pot;
Increase the workpiece temperature, reduce the heat loss of zinc liquid, and ensure uniform adhesion of the coating.
4.What is the preheating temperature standard?
General requirements: The preheating temperature of the workpiece needs to reach 100-150℃, and the temperature of complex workpieces or thick plates can be appropriately increased to 180℃.
Risk of insufficient temperature: Residual moisture causes zinc liquid to splash, and the temperature difference between the workpiece and the zinc liquid is too large, which can easily cause uneven coating thickness.
5.How to match galvanizing time and temperature?
High temperature and short time: suitable for thin steel plates (such as ≤2mm) to avoid excessive coating; Low temperature and long time: suitable for thick steel plates (such as ≥5mm) to ensure sufficient diffusion of zinc liquid.