Stainless Steel Pickling, restoring the protection of the metal’s surface layer
Restore the surface layer
Among the services offered by Bama is the stainless steel pickling process. Stainless steel is by definition stainless, so a pickling process might seem unnecessary.
In reality, even materials like stainless steel can, under certain circumstances, lose their characteristics and require a treatment to restore them.
Stainless steel pickling is carried out whenever stainless steel undergoes a treatment that somehow attacks its passivating surface layer, such as welding.
In these cases, the "protection" of stainless steel – provided by chromium – is lost, and the material becomes vulnerable to external agents.
Which agent to pick
Stainless steel pickling is the only process capable of restoring stainless steel's rust resistance, necessary for continuing the processing cycle with subsequent passivation and electropolishing.
In these cases, the “protection” of stainless steel – provided by the chromium content in the alloy – is lost, and the material becomes vulnerable to external agents.
The methods used for stainless steel pickling vary depending on the characteristics and size of the area or item undergoing the treatment.
For small interventions, the area can be manually covered using a brush. For larger objects, there is the possibility of spraying the entire area, including joints or difficult-to-reach points. Finally, like with degreasing, stainless steel pickling can be done by immersing the entire object.
In all three cases, the substances used for pickling are primarily solutions containing hydrofluoric acid, nitric acid, and water. However, there are methods to avoid the use of nitric acid in favor of eco-friendly substances. Bama uses Bama Ecodec, a liquid product free from nitric acid.
The immersion tanks themselves are specially treated to resist acid action, and a meticulous protocol is implemented to ensure correct storage of all materials used.
