Passivating
Passivating
(OP)
Can someone explain to me exactly what passivating does to metal? We currently passivate thin steel (0.020" thick), then handle it (no gloves), machine it, perforate it, etc. I thought it was a cleaning process. Handling it after the fact does not make sense to me, but perhaps I have the wrong idea about what it actually does.





RE: Passivating
RE: Passivating
Tom
RE: Passivating
RE: Passivating
RE: Passivating
Other replies also correctly point out that nitric acid passivating solution will remove iron contamination, rust from which also a compromises the passive film uniformity. Passivation does not remove heat tint or welding scales - pickling is required.
You can handle passivated stainless steel reasonably normally without any downside - think of it as a rugged, very thin ceramic coating that can be broken/scratched off mechanically.
RE: Passivating
The many response are correct. Sum up the responses and you have the solution.
The best source is ASTM A 967 & ASTM A 380.