Passivation is intended to improve the corrosion resistance of parts made from austenic, ferritic and artensitic corrosion-resistant steels of the 200, 300 and 400 series and precipitation hardened corrosion-resistant steels. Grades 440C may be exempt from passivation treatments at the discretion of the procuring activity. The type of passivating is alloy specific.
Type II: Medium temperature nitric acid solution with sodium dichromate additive.
Type VI: Low temperature nitric acid solution.
Type VII: Medium temperature nitric acid solution.
Type VIII: Medium temperature; high concentration nitric acid solution.