More about Surface Treatments
Want to learn more about Calamo’s passivation expertise and the industry standards we follow? Read more about passivation, pickling and electropolishing.
Effective method
Passivation – Treatment to Strengthen Protective Layers
Through treatment with a mild acid – an oxidizing agent – passive surfaces that have been lost during mechanical polishing or grinding can be restored. This is why passivation is an effective method to strengthen the passive layer, an integral part of Calamo's high-quality surface treatment offerings.
Reinforcing Stainless Steel’s Natural Protection
Achieving long-term corrosion resistance requires precise surface treatment methods that enhance material integrity. Passivation strengthens stainless steel’s natural protective oxide layer, ensuring optimal durability and corrosion resistance.
Preserving Surface Smoothness
One of the key advantages of passivation is that it does not affect surface smoothness, making it an ideal treatment for ground or blasted surfaces.
What is Passivation?
- Passivation is a chemical treatment using a mild acid (oxidizing agent) to strengthen the protective oxide layer on stainless steel.
- During mechanical polishing or grinding, the surface becomes active, losing its passive properties.
- To restore corrosion resistance, the passive layer must be recreated under controlled conditions. If this happens spontaneously with the presence of foreign particles on the surface, they will remain in the passive layer, potentially providing less corrosion protection than creating the oxide layer through a controlled process.
Read more about Passive Layers and Passivation.
Chemical Post-Treatment – Different from Pickling
Passivation serves as a chemical post-treatment for mechanically processed components that have not undergone annealing. Finely sanded and blasted surfaces particularly benefit from passivation, as it enhances surface integrity without altering material properties. While a passivation bath resembles pickling, it contains higher acid content and functions differently.
Passivation – A Milder Process
Unlike pickling, passivation does not contain an activator, making it a gentler treatment. It does not remove annealing oxides or other chromium oxides, preserving the structural integrity of stainless steel surfaces.
Post-Treatment for Electropolishing
Passivation can also be applied as a post-treatment for electropolishing, increasing the thickness of the passive layer and enhancing the surface’s hydrophobic properties.