Zinc plating refers to the surface treatment technology of plating a layer of zinc on the surface of metals, alloys or other materials to make them beautiful and rust-proof. The main method is hot dip galvanizing.

In the actual production process, the common factors affecting the speed and quality of galvanizing are as follows:

(1) Pretreatment is not thorough. There is oxide film on the surface of workpiece, which affects the normal deposition of zinc.

(2) Poor conductivity. The current is consumed on the wire, and the current allocated to the surface of the workpiece is too small.

(3) High carbon content of workpiece. High carbon steel and iron castings will reduce the potential of hydrogen precipitation, accelerate the hydrogen evolution on the surface of the workpiece, and reduce the current efficiency.

(4) The workpiece is too tightly bound. When galvanizing, the part of the workpiece is shielded and the coating is too thin.

(5) The bath temperature is low. When the bath temperature is low, the current density of distribution decreases correspondingly, and the deposition rate of the coating decreases inevitably.

(6) The content of sodium hydroxide in the plating bath is on the high side. When the content of sodium hydroxide is higher, the current efficiency decreases accordingly.

(7) The additive content in plating bath is low. The low content of additives will affect the dispersing ability, and the coating is too thin locally.

(8) Due to insufficient estimation of plating area, the current density of distribution during plating appears to be too small.

(9) The workpiece suspension method is inappropriate and the distance between the workpiece and the zinc anode is too large, so the position should be adjusted.

(10) Over-corrosion of workpiece. Reducing the potential of hydrogen precipitation reduces the current efficiency of hydrogen precipitation acceleration on the workpiece surface, thus affecting the deposition rate of zinc. A proper amount of corrosion inhibitor should be added to the pickling solution, and the oxide scales at the local areas should be removed by mechanical method first, and more checks should be made during the pickling process.

(11) Anodic passivation. The reduction of effective area affects the normal distribution of current.

(12) The content of sodium hydroxide is low. If the content of sodium hydroxide is low, the current density will not increase and the anode will be passivated.

These factors will affect the speed and quality of galvanizing, if you want to learn more, you can feel free to contact us.Email:sales@haihaogroup.com