The color of the passivation film has changed. Is this related to the quality of the trivalent chromium colored zinc passivating agent? Actually, it may not be. Sometimes, it is related to these factors below.
The zinc layer is too thin
The thin zinc coating has larger pores, which can easily form micro-batteries, thereby accelerating its corrosion. The initial sign of corrosion is the discoloration of the passivation film. Then you will notice that the film layer grows white hairs. Subsequently, the zinc coating dissolves rapidly, and finally, rust spots appear on the film layer.
Therefore, as a manufacturer of trivalent chromium chromate zinc passivation agents, Bigely suggests that to avoid such problems, the plating time can be appropriately extended and the zinc coating thickness can be increased to prevent color changes.
The passivation film is relatively thin
A thinner passivation film is a common cause of discoloration. So what factors can lead to a thinner passivation film? We believe that the core influencing factor is the passivation time. Taking the trivalent chromium colored zinc passivating agent Zn-228 as an example, if the passivation time needs to be maintained at more than 60 seconds, a too short time will directly result in a too thin film layer.
In actual production, the passivation time needs to be adjusted according to the concentration of the passivation solution and its expiration date. The adjustment can be carried out under the guidance of the Bigely engineers.
About us
Guangdong Bigely Technology Co., Ltd. ,founded in 2003, is a high-tech enterprise integrating R & D，production, sales and service, specializing in the production of electroplating additives. As a famous electroplating additives source manufacturer in China, Bigely has over 20 years' experience in electroplating additives production and own production base of 5000 square meters. We can produce 15,000 tons of electroplating additives every year, which can fully meet the needs of customers.
If you need our high-quality electroplating additives, please contact us. We can provide you samples for test, and also provide a series of services.
