A process designed to remove foreign metals from the surface of stainless and corrosion resistant steels by immersing a cleaned and desealed steel part in a solution of nitric acid and oxidizing salts.
This process dissolves exposed surface iron and produces a transparent film of corrosion-resistant chromium oxide.
Does not change the appearance of the base metal.
Type I Low Temperature Type 11 Moderate Temperature Type III High Temperature Type IV For Steels containing large amounts (0.15 % ) of sulfur or selenium. Type V Anodic - For high carbon martensitic Type VI Low Temperature.