Common factors affecting the speed and quality of galvanizing

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 pretreatment

There is an oxide film on the surface of the workpiece, which affects the normal deposition of zinc.

(2) Poor conductivity

The current is consumed on the wire, and the current distributed to the surface of the workpiece is too small.

(3) The carbon content of the workpiece is high

High carbon steel, cast iron parts, etc. will reduce the hydrogen precipitation potential, accelerate hydrogen precipitation on the surface of the workpiece, and reduce the current efficiency.

(4) The workpieces are tied too densely

The workpiece is partially shielded during galvanizing, resulting in a thin coating.

(5) The plating solution temperature is too low

When the plating solution temperature is too low, the current density distributed is correspondingly reduced, and the deposition speed of the coating is inevitably reduced.

(6) The sodium hydroxide content in the plating solution is too high

When the sodium hydroxide content is too high, the current efficiency is correspondingly reduced.

(7) The additive content in the plating solution is too low

The low additive content will affect the dispersion ability, and the coating will appear too thin locally.

(8) The area of the plated part is underestimated, and the current density distributed during plating appears too small.

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

(10) Over-corrosion of the workpiece

Reducing the hydrogen deposition potential, hydrogen deposition on the workpiece surface accelerates the current efficiency, thereby affecting the zinc deposition rate. An appropriate amount of corrosion inhibitor should be added to the pickling solution. If the oxide scale is too thick in some places, it should be removed mechanically first. Check more during the pickling process.

(11) Anode passivation

The effective area is reduced, affecting the normal distribution of current.

(12) Low sodium hydroxide content

If the sodium hydroxide content is low, the current density cannot be increased and the anode is passivated.