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316L is rusting

We have a cart fabricated with 3/16 x 2" square tubing 28" x 42" x 44". It is made with 316L stainless steel, but it is rusting immediately after being cleaned with a clorox/water solution. We also have a cabinet 14" x 33" x 69" with the same scenario. The first time it rusted we sprayed it with a heated citric acid and polished it then passivated it with a different grade citric acid . It is still rusting

Bruce Cloud
- Bells, Tennessee, USA
2002

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Bleach is one of the worst things that you can put on stainless steel. You have found this out. After you cleaned off the rust and repassivated with the citric formulation, did you re-expose it to the bleach to cause the further rusting, or did you not get all of the iron off the first time. Warm citric acid formulations will do a good job of removing all of the rust and free iron. It will not return unless you stress the surface with more bleach or other corrosive material.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2002

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As nice as 316L SS is, it has no defense against chlorides and it will corrode spontaneously. There are other grades of stainless formulated for standing up to wet chlorides, but 316L is never recommended for wet chloride service.

Dave Kinghorn
Chemical Engineer
SUNNYvale, California
2002