Influencing factors of galvanizing

Influencing factors of galvanizing

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

(1) Pre-treatment is not thorough. The surface of the workpiece has oxide film, which affects the normal deposition of zinc.

(2) poor conduction. The current is consumed on the wire, and the current distributed to the workpiece surface is too small.

(3) the workpiece has a high carbon content. High carbon steel and cast iron can reduce hydrogen precipitation potential, accelerate hydrogen evolution on workpiece surface, and reduce current efficiency.

(4) The workpiece bundling is too dense. Galvanized workpiece is partially shielded resulting in thin coating.

(5) the bath temperature is low. When the bath temperature is low, the current density of distribution will decrease accordingly, and the deposition rate of the coating will also decrease.

(6) the content of sodium hydroxide in the plating solution is high. The current efficiency decreases when the sodium hydroxide content is high.

(7) the additive content in the plating solution is low. The low additive content will affect the dispersion ability, and the coating appears too thin locally.

(8) The estimated area of plated parts is insufficient, and the current density of distribution during plating is too small.

(9) Improper workpiece suspension method, and zinc anode spacing is too large, should be adjusted position.

(10) workpiece corrosion. With the decrease of hydrogen precipitation potential, the efficiency of hydrogen evolution acceleration current on workpiece surface decreases, which affects the deposition rate of zinc. Appropriate amount of corrosion inhibitor should be added to the pickling solution. The local oxidized skin is too thick and removed by mechanical method first. Check more in the pickling process.

(11) anode passivation. The effective area is reduced, which affects the normal distribution of current.

(12) Low sodium hydroxide content. If sodium hydroxide content is low, the current density is not high, anode passivation.