Quality control of large roll galvanized wire coating

1. Adjust electroplating process parameters

Strictly control the pH value of large roll galvanized wire bath, research shows that the size of the bath pH value directly affects the quality of steel wire coating, improper control of pH value will cause loose coating. When the pH value is greater than 3, the steel wire coating has burr caused by fine dendrites, and the surface is not smooth. The current density is strictly controlled. From the microscopic morphology, the higher the current density, the larger the zinc layer grain deposition, the less dense the corresponding zinc layer.

On the contrary, the denser the ion deposition, the better the quality of zinc layer. Under the condition that the surface zinc layer is dense and bright, the quality of zinc layer per unit area should reach 80g/m2, and the process parameters should be optimized as follows: current density is 16-20A /dm2, mass concentration of zinc sulfate solution is 500g/L, and pH value is 2.5-3.0.

galvanized wire

2. Adjust the drawing process parameters of the water tank

In strict accordance with the multi-pass small compression rate drawing, the total compression rate is 96.48%, reducing the scraping of zinc layer. The whole wire drawing die is made of tungsten steel die and polycrystalline die. The Angle of the working cone of the wire drawing die is 12° ~ 16°, and the length of the sizing belt is 0.15 of the diameter of the wire, so as to ensure that the deformation of the zinc layer is basically synchronous with the steel wire substrate.

The cooling circulation system uses spray to cool the drawing die, and takes away a lot of heat generated by the drawing machine in high speed drawing in time to ensure the quality of the wire. Control drawing process parameters: drawing speed 10 ~ 12m/s; Winding tension 8 ~ 10N; Measuring length 30km; The mass fraction of lubricant is 3.5 ~ 4.5%; pH value of lubricant 7 ~ 8; Lubricant temperature 30 ~ 40℃.

After the optimization of the process, mass production of 0.80mm electro galvanized steel wire electro galvanized zinc layer quality is controlled within 80 ~ 90g/m2, zinc layer quality dispersion is very small; The results show that the average weight of zinc layer is 14.5g/m2, the loss of zinc layer is less than 5%, and the tensile strength of steel wire is 2300 ~ 2500MPa. It not only effectively controls the quality of zinc layer of raw steel wire, but also reduces unnecessary waste and production cost.


Post time: 04-05-23