What are the hazards of Fe in zinc solution?

Solubility of iron in pure zinc. The solubility of iron in pure zinc is 0.02%. The other phases mainly exist in the form of Fe3Zn10 (Γ ordered body-centered cubic crystal), FeZn10 (δ1 hexagonal crystal), and FeZn13 (ξ face-centered monoclinic crystal). Their expressions are as follows Zinc slag.

Iron is one of the harmful impurity elements, which mainly manifests itself in the following two aspects: (1) Form zinc slag and reduce the effective utilization rate of metallic zinc.

During the heating process, the iron in the zinc liquid is in an unsaturated state

The iron on the inner surface of the zinc pot will enter the zinc liquid.

The iron in the workpiece entering the zinc liquid will lower the local temperature of the zinc liquid, reduce the melting degree, and eventually form zinc slag.

The iron in the plating aid film attached to the workpiece is brought into the zinc solution.

The iron in the base of the workpiece is melted into the zinc liquid.

(2) Affects the surface quality of the galvanized layer.

Iron exists in various complex intermetallic compounds in molten zinc:

The viscosity of the zinc liquid greatly increases, which reduces the fluidity of the zinc liquid, eventually leading to quality problems such as thickening of the galvanized layer and rough surface.

Hot-dip galvanizing companies should pay special attention to the iron ion content in the zinc pot.