1. There are some problems during the process of surface cleaning. The galvanized steel coil substrates are not cleaned well and cause internal oxidation.
2. After coming out of the zinc pot, the zinc layer thickness of the galvanized steel sheet is not uniform due to the cause of the nozzle.
3. Check if the temperature of zinc solution is qualified, low temperature will also cause fall off.
4. Air-fuel ratio is unreasonable, low hydrogen flow, furnace has oxygen infiltration and the strip wok temperature is low.
5. Oil evaporation is not enough, the aluminum content in zinc pot is low, the unit speed is too fast, the reduction is not sufficient, zinc solution in the residence time is too short.
6. External force collision and beat can make the zinc layer off, especially at the corners.
After galvanize on the steel sheet, it can greatly extend the service life, and the galvanized quantity also has a close relationship with the corrosion resistant performance of galvanized steel coil. Therefore, CAMELSTEEL reminds that, in order to improve the corrosion resistance and service time, we must pay attention to the above reasons of zinc lay off during the produce process of galvanized steel coil.