Why is the product quality of dry process hot-dip galvanizing better than that of wet process?

In "dry process" hot-dip galvanizing, aluminum can be added to the zinc bath to improve the structure and thickness of the iron-zinc alloy layer, resulting in a bright pure zinc layer and good bending performance. Meanwhile, during hot-dip galvanizing, the flux has already been applied to the surface of the steel pipe, and the zinc chloride in the flux has begun to react slightly with the steel substrate. As the temperature of the steel pipe rises during drying, the reaction accelerates. Therefore, once the steel pipe is submerged in the zinc bath for galvanizing, the iron-zinc reaction reaches its peak. This ensures sufficient reaction time between iron and zinc from the application of the flux to the immersion in zinc, making it less likely for missed galvanizing to occur. However, the "wet process" hot-dip galvanizing lacks these favorable conditions. Firstly, aluminum cannot be added to the zinc bath surface. Even if aluminum is added, it reacts with the chloride flux to form aluminum chloride, which then volatilizes. Additionally, in the "wet process" hot-dip galvanizing, the steel pipe only begins to contact a thin layer of flux on the zinc bath surface when it is not yet coated with zinc. This results in a very short time for flux application and weaker chemical cleaning power, insufficiently activating the surface of the steel pipe. This affects the iron-zinc reaction and increases the likelihood of missed galvanizing.