Often stainless steels are compromised by free iron on the surface of the alloy often picked up as ‘tramp’ materials from cutting tools etc. used in the manufacturing process. These can obviously be detrimental to components and services causing rust and corrosion.
Passivation is a finishing process to improve the corrosion resistance of the Stainless Steel by removing this ‘free iron’. The process is carried out by the removal of any surface iron compounds (free iron) by using an oxidising acid solution. Subsequently a new oxide film is formed on the surface of the stainless steel in a controlled fashion.
This process is often used where maximum corrosion resistance is critical such as the aerospace, defence, medical and food industries.