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Does chlorine from insulation attack stainless steel at 450 C?

DEAR ALL,

I WANT TO KNOW WHETHER INSULATED STAINLESS STEEL WITH TEMPERATURE ABOVE 450 DEG C NEEDS ANY COATING TO PROTECT IT FROM CHLORINE ATTACK (EXIST IN INSULATION MATERIAL) OR NOT?

KIND REGARDS,
ZAREI

ENAYAT ZAREI
- SHIRAZ, IRAN
April 28, 2008

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It is always best to keep any chlorine away from stainless steel, if possible. At 450 deg C it is quite possible to have attack by chlorides in the insulation. It is best to use a non-chlorine containing insulation if possible.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

June 4, 2008

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June 12, 2008

Some critical applications specify a barrier to isolate the stainless steel from the insulating material.
We have to use an aluminium foil which would help in your case.
Keeping the insulating material dry if possible is of course also important.
Regards,

Martin Rich
ship repair - Plymouth, UK

Stainless steel degradation due to corrosion under insulation is normally not present at 450°C. The technical system is to hot, water will vaporise and chlorine will be could in the insulation. However if there are defects in the insulation corrosion chlorine attack be a problem. Check the chlorine contamination in the air and check for coldspots. Take away the insulation where you expect stress in your system and look for stress corrosion.

Wim van Leeuwen
- Hellevoetsluis, zuidholland, Netherlands
February 16, 2009