Some steel grades are not suitable for pickling or electrochemical polishing. Passivation does not change neither surface structure of article, nor its macroscopic properties, but substantially improves corrosion resistance. Some steel grades are not suitable for pickling or electrochemical polishing. They, being stainless, have to low content of chromium and nickel alloy additions. To improve their corrosion resistance, chemical passivation is used. This passivation does not change neither surface structure of article, nor its macroscopic properties, but substantially improves corrosion resistance.

Stainless steel after passivation

Cleaning and passivation process can remove dirt and discoloration from the surface of soldered parts made of copper and brass. On a clean surface, at the next stage of the process, is produced organic passive layer which largely protects the surface from oxidation.