- Sep 17, 2018 -
1. Nickel content of plating: The corrosion resistance of the coating has a close relationship with the nickel content. Both the test and related materials have proved that the zinc-nickel alloy coating with a nickel content of about 13% has the best corrosion resistance. Therefore, the nickel content of zinc-nickel alloy is usually controlled within the range of 8-16%, which can meet the requirements of corrosion resistance.
2, the thickness of the coating: usually the thickness of the coating is 5-15μm to meet the corrosion resistance requirements. For components without tolerance requirements, such as guardrails, the thickness can be more than 20μm.
3. Passivation film quality: The corrosion resistance of zinc-nickel alloy is greatly improved after passivation treatment. The passivation film is divided into three types: white, black and five colors. The order of corrosion resistance is: white passivation, black passivation, and multicolored passivation.
4, coating bonding force: according to gb5270 multiple methods of testing qualified.
5. Corrosion resistance: After the multi-pass passivation of the coating with a nickel content of about 13%, the neutral salt spray test does not show red rust for more than 2500 hours, and it is expected to withstand atmospheric corrosion for more than 15 years.