The passivation process returns the stainless steel back to its original specifications and therefore the life of the product is extended. When a part is machined it can become more susceptible to free iron corrosion and for this reason the passivation treatment is also known as ‘decontamination’.
Stainless steel is a chrome alloy and is well known as being resistant to chemical corrosion. The surface which is exposed to the corrosive environmental factors is covered with a passive coating of chromium oxide which in turn is an integral part of the alloy itself.
Although this film is continuously and naturally created and recreated by the oxygen absorbed by the metal surface, it is very susceptible to contamination (from residue metals, dirt, dust, etc.) compromising its homogeneity and resistance and therefore causing the technological properties of the product to deteriorate. For this reason the passivation treatment of stainless steel is considered to be both important and useful.