Stainless steel can corrode in service if there is contamination of the surface.
Both pickling and passivation are chemical treatments applied to the surface of stainless steel to remove contaminants and assist them formation of a continuous chromiumoxide, passive film.
Pickling and passivation are both acid treatments and neither will remove grease or oil.
If the fabrication is dirty, it may be necessary to use a detergent or alkaline clean before pickling or passivation.
Stainless steel pickling is the most common pickling process used at Metapic’s facility. The most common application for stainless steel pickling is to “ pickle / passivate ”.
This is a one-step process which removes heat tint and weld scale while simultaneously passivating the surface of the parts being processed.Most customers are surprised to find out that pickling also accomplishes passivation.
However, where required by our customers, Metapic will pickle and passivate in two complete and separate steps.
The importance of pickling, passivating and cleaning Stainless Steel cannot be stressed enough.
These processes remove rusts, heat scales, weld contamination and can detect faults in the product. Furthermore, stainless steel can acquire surface contamination even in non-corrosive environments.
Therefore, the possibility of corrosion is greatly reduced and the life of the treated stainless steel increased. Metapic procedures are generally in acordance with ASTM A380.