1, spring plating after the diameter difference.
Reason: The spring line to be plated by the super-difference, when plating the spring surface zinc volume is not uniform.
Solution: Treat the pre-plating inspection of the plating spring, find that the super-difference line is processed in a timely manner;
2, the surface of the zinc layer in the rope, strands when there is a phenomenon of peeling;
Reason: The spring is not clean before plating, resulting in poor binding force between zinc and steel-based surface, zinc-plated spring in plating, the deposition speed is too fast, the surface of the zinc layer is rough, not dense, the use of the pre-deformation is unreasonable, resulting in scraping.
Methods to solve the zinc layer shedding method: increase the concentration of electrolytic acid wash, electrolytic alkali washing solution or increase electrolytic acid washing, electrolytic alkali washing current;
3, the surface coating is not uniform thickness;
Reason: the surface of the cathode gun head is not clean, affecting the conductivity of the spring and cathode gun, resulting in the current instability of the spring to be plated;
The method of solving the zinc layer unevenness: often clean the surface of the cathode gun head to ensure normal contact with the cathode, often adjust the zinc block with the spring to be plated, zinc block reduced to a certain extent, to be replaced often.
4, the surface coating has black imprint;
Reason: The spring surface after chemical acid wash is not rinsed cleanly, the cathode gun head is in poor contact with the spring surface, the head of the gun has black oxide stuck to the metal spring, in galvanizing when covered with zinc atoms.
The solution to the zinc layer has a black stamp: chemical acid wash to wash the spring surface clean;