GI sheets are widely used in many industries today. Therefore, we know the possible quality problems and reasons of GI sheet. Can effectively avoid these problems to a certain extent, or know how to prevent them.
(1) Defects of the original board
The original board of GI sheet will have problems including creases, pits, wavy edges, etc. Therefore, inspection of the original board before production can effectively avoid this problem.
(2) Dark spots
The purity of the galvanized layer is not enough, and it is easy to produce black spots on the surface of the GI sheet. After the GI sheet is passivated, due to the high content of impurities such as copper and iron in the zinc layer, it is easy to form black spots. Therefore, we should choose a large-scale manufacturer with quality assurance for production and processing.
(3) White rust
When the surface of GI sheet is damp, at a certain temperature, the zinc layer is oxidized to produce white powder, and the generation of white rust will greatly reduce the anti-corrosion ability of the surface of GI sheet. Therefore, when storing GI sheet, care should be taken to keep the storage environment dry.
(4) Scratches and abrasions
When the GI sheet passes through the tension leveler, there are foreign objects in the leveler that cause surface scratches, abrasions, etc. Care should be taken during the production process.
(5)
Chromic acid dirt
In order to improve the anti-corrosion ability of GI sheet, a very thin passivation layer is formed on the surface of GI sheet, which can be completed by chromic acid treatment, that is, chromating treatment. However, if the chromic acid treatment is not good and there is residual liquid, the surface of the GI sheet will appear yellowish bands or stains, or even black spots.
