Finishing Treatments: Passivation

Technical Information

Semi-finished or finished parts are usually treated for passivation. The standard practice is to passivate parts after machining, grinding, or lapping. The reasoning is to address iron particles that may be embedded or smeared on the surface of stainless steel components during manufacturing. If allowed to remain, the iron corrodes stainless steel.

If the parts have flux or slag from welding or high-temperature brazing, they should be removed by chipping, brushing with stainless-steel wire brush, grinding, or polishing with an iron-free abrasive. Cleaning should begin with solvent cleaning followed by an alkaline soap cleaning and thorough water rinsing. The best results are obtained in passivation when the parts are cleaned as thoroughly as possible.