?1. Defect Name: galvanized steel coil - galvanized stripping
Defect performance: dezincification
Cause: Poor furnace temperature, improper handling of the substrate of
prepainted galvanized steel coil in stock, etc.
2. Defect Name: galvanized steel coil - ungalvanized
Defect performance: the surface of the steel plate is not galvanized
Causes: poor raw materials, poor pre-treatment degreasing, poor furnace temperature
3. Defect Name: galvanized steel coil - poor zinc flower
Defect performance: zinc flower size of prepainted galvanized steel coil in stock is uneven, no zinc flower
Cause: poor furnace temperature rise, poor cooling control
4. Defect Name: galvanized steel coil - zinc bismuth
Defect performance: spotted on the surface of the coil, attached to the granular zinc residue
Cause: The scum or bottom slag in the zinc pot is attached to the steel strip.
5. Defect Name: galvanized steel coil - oxidation
Defect performance: white rust
Cause: During the storage process, it absorbs moisture from the air and oxidizes.
