In modern industry, trivalent chromium colored zinc passivation process is widely used in the electroplating processing industry for its good corrosion resistance and environmental advantages. However, in practice, iron impurities in the passivation solution often adversely affect the appearance and quality of the film layer. In order to ensure the stability of the passivation process, we need to gain a deeper understanding of how iron impurities affect the process and use suitable passivators to meet this challenge.
In the trivalent chromium colored zinc passivation process, there are two main pathways for the introduction of iron impurities: one is from the production process of the passivation solution, and the other is from the contact between the galvanized parts and the passivation solution during the passivation process. However, either way, once the iron impurities enter the passivation solution, a series of adverse reactions will be triggered.
Studies have shown that iron impurities react with trivalent chromium ions in the passivation solution to form insoluble precipitates. These precipitates not only affect the uniformity of the passivation layer, but also lead to defects such as spots and uneven color on the surface of the film layer, which seriously affects the appearance and corrosion resistance of the product.
Iron impurities on the galvanized layer passivation film stability and aesthetics have obvious destructive effect. The presence of iron impurities will accelerate the consumption of trivalent chromium ions, resulting in a slowdown in the formation of passivation film, and ultimately make the film layer thin, brittle and easy to fall off. Moreover, high iron concentration will make the passivation solution lose passivation ability, so that the color film layer can not be formed normally.
Under this background, the use of trivalent chromium colored zinc passivates with high resistance to iron impurities is particularly important. The trivalent chromium colored zinc passivate BZ-208 from Bigely is designed to solve this problem. It offers good resistance to iron impurities and passivates a pleasing colored film appearance under normal operation. In addition, BZ-208 is unique among high corrosion resistant trivalent chromium iridescent passivates in its ability to improve the corrosion resistance of the film.
In summary, by choosing trivalent chromium colored zinc passivators with strong resistance to iron impurities, such as Bigely BZ-208, the adverse effects of iron impurities on the passivation process can be effectively counteracted, thus providing good surface protection and beautiful appearance for the products, and enhancing the market competitiveness of the products.
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