Common factors affecting the speed and quality of galvanizing

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

(1) incomplete pre-treatment.The oxide film on the surface of the workpiece affects the normal deposition of zinc.

(2) poor electrical conductivity.The current is consumed on the wire and the current allocated to the workpiece surface is too small.

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

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

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

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

(7) low additive content in the bath.Low additive content will affect the dispersion ability, the coating appears too thin locally.

(8) the area of the plated parts is not estimated, and the current density distributed during plating is too small.

(9) the position of the workpiece should be adjusted if the suspension method is improper and the spacing between the workpiece and the zinc anode is too large.

(10) over corrosion of the workpiece.When the precipitation potential of hydrogen is reduced, the accelerated current efficiency of hydrogen evolution on the workpiece surface is reduced, which affects the deposition rate of zinc.Should add the right amount of corrosion inhibitor in the pickling solution, local oxidation skin is too thick by mechanical method to remove first, pickling process for more inspection.

(11) anodic passivation.The decrease of effective area affects the normal distribution of current.

(12) low content of sodium hydroxide.If the sodium hydroxide content is low, the current density is not high, and the anode is passivated.