Treatment process: passivation
We know that metal products are easily corroded. In order to prolong the life of metal products and improve the anti-corrosion ability of metal products, they must be passivated and protected. Our common metal objects such as ships and automobiles are passivated. processed.
What is Passivation?
is a method that converts the metal surface into a state that is not easily oxidized and delays the corrosion rate of the metal. In addition, the phenomenon of an active metal or alloy in which the chemical activity is greatly reduced and becomes a noble metal state is also called passivation.
If the corrosion product generated by the metal due to the action of the medium has a dense structure and forms a thin film (often invisible), which closely covers the surface of the metal, it changes the surface state of the metal and becomes a passive state of corrosion resistance.
Passivation treatment is the last process step in chemical cleaning and a key step, and its purpose is to prevent corrosion of materials.
For example, after the boiler is pickled, rinsed, and rinsed, the metal surface is very clean, very activated, and easily corroded. Therefore, passivation treatment must be performed immediately to form a protective film on the cleaned metal surface to slow down corrosion.
Compared with other surface treatment processes, passivation treatment has the following advantages:
1) has the characteristics of absolutely not increasing the thickness of the workpiece and changing the color, improving the precision and added value of the product, and making the operation more convenient;
2) Since the passivation process is carried out in a non-reactive state, the passivation agent can be added and used repeatedly, so the service life is longer and the cost is more economical.
3) Passivation promotes the oxygen molecular structure passivation film formed on the metal surface, the film layer is dense and stable, and it has a self-repairing effect in the air. Therefore, compared with the traditional method of applying anti-rust oil, passivation formed. The film is more stable and more resistant to corrosion.