What are the effects of insufficient coating thickness on galvanized products? How can it be improved?
An excessively thin coating significantly reduces corrosion resistance and shortens service life. The immersion time can be appropriately extended, the current density adjusted, and the zinc bath composition optimized to ensure the coating reaches the standard thickness.
Is an excessively thick coating harmful to galvanized products?
Yes, it is harmful. It not only increases production costs but may also lead to increased coating brittleness, affecting subsequent processing. For example, it can easily cause cracking and peeling during stamping and also affect product assembly accuracy.
How to solve the problem of yellowing trivalent chromium passivation film?
This is often due to excessive iron impurities in the passivation solution or contamination of the brightening solution. In this case, the passivation solution and brightening solution should be replaced promptly to prevent impurities from continuously affecting the passivation effect.
What precautions should be taken when storing galvanized products?
They should be stored in a dry, ventilated place. Outdoor stacking requires covering and padding. Avoid storing them with corrosive media such as acids and alkalis. Passivated products must be thoroughly dried to prevent residual moisture from causing oxidation.
What are the length tolerance requirements for galvanized steel sheets?
Negative length tolerances are not allowed, and the maximum deviation cannot exceed +6mm.