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Oxidizing of Stainless Steel in DIO3

I have a problem with my Stainless Steel parts oxidizing in DIO3 (Ozone saturated Deionized water) cleaning baths. Is there a method to passivate the metal to prevent this from occurring. I'm not exactly sure which SS alloy we are using but it may be 304 or 316.

John Phillips
photomasks - Poughkeepsie, New York,USA
2000

Dear John:

DIO3 is an aggressive solution, but others have had success with 304 & 316ss with adequate passivation. Are the parts electropolished? Have they been passivated previously? What kind of oxidation are you talking about occurring? We assume that you are getting red iron oxide if you are saying that you are having a problem. This should be preventable by getting the best Chromium oxide layer that you can on the surface.

Let us know if we can help by running some tests. Lee

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2000

John Phillips, Sounds like you have a fundamental parts problem. Ozonated DI will oxidize any contaminants present on the steel surface. You need to ensure the only chemical species present on the surface is the auto-catalytic chromium. There are about n+1 ways to do this. Which ever technique you use must be capable of dealing with the surface contaminates present. These contaminates are rarely restricted to iron oxides.

Hamish Hunt
- Melborne, Australia
2000