The term passivation can have various meanings. It can refer to the process where stainless steel spontaneously forms a protective oxide layer when in contact with oxygen. It can also involve cleaning a surface from substances that could cause corrosion – for example, iron particles.
When we at Calamo refer to passivation, we are referring to a treatment with a weak acid (oxidizing agent) to enhance the protective oxide layer.
During mechanical polishing or grinding of stainless steel, the surface becomes active and loses its passive properties. To regain corrosion protection, the passive surface needs to be reestablished. If this occurs spontaneously with the presence of foreign particles on the surface, they will remain in the passive layer. This may provide less protection against corrosion than creating the oxide layer through a controlled process.
In simple terms, the measures taken to protect a stainless steel surface from corroding through a protective oxide layer constitute passivation.
If you want to learn more about passivation or have questions about the different standards, please contact our sales department