When the galvanizing plant uses trivalent chromium blue zinc passivation agent for production, if the salt spray resistance of the workpiece coating is not good, it will affect the quality of the workpiece.Especially in the rainy season, some workpieces have been corroded during transportation and storage. Is this trivalent chromium blue zinc passivator not easy to use?
Bigolly Technology made an analysis based on the field experience and the characteristics of the product trivalent chromium blue zinc passivator BZ-212,this is not actually the case, there may be 4 reasons:
1. Control of passivation solution.In the production process, it is very important to control the concentration, pH value and temperature of the passivation solution.They not only determine the color of the passivation film, but also control the film formation speed of the passivation film.Generally, the film forming speed is fast, the film layer is rough, and the salt spray resistance effect is not good.
2. Baking and aging treatment after workpiece passivation is necessary.After the workpiece is passivated, the baking temperature is 60~80℃, and the baking time is 10~15 minutes.Baking treatment can dry the moisture on the surface of the workpiece, and make the passivation film denser and more resistant to salt spray.
3. Control of zinc and iron impurities in passivation solution.Generally, the zinc impurity concentration should be lower than 5g/L, and the iron impurity concentration should be lower than 50ppm.The high impurity concentration will affect the appearance of the passivation film, such as the phenomenon of blooming and fogging; it will also affect the salt spray resistance of the workpiece.In the production process, the workpieces falling in the passivation tank should be salvaged frequently to prolong the service life of the passivation solution and improve the salt spray resistance of the workpieces.
4. The performance of trivalent chromium blue zinc passivator.There are many trivalent chromium blue zinc passivators on the market.However, due to the formula of some passivators, the passivation film of the workpiece is not dense after passivation, and the salt spray resistance effect of the galvanized layer cannot be better improved.Therefore, the trivalent chromium blue zinc passivator with uniform appearance and excellent performance should be selected, such as BZ-212 of Bigolly, which can resist salt spray (white rust) for more than 96 hours.
Therefore, the poor salt spray resistance of blue zinc workpieces is not necessarily because the performance of the trivalent chromium blue zinc passivator is not good. It may be that the control of the passivation solution is not in place.In addition, the workpiece is bumped during transportation, and the salt spray test is carried out after production, and the salt spray effect is not good.If you are interested in trivalent chrome blue zinc passivator,please contact Bigolly customer service, you can get free samples and detailed technical information!
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