NOTICE

Forums are temporarily disabled while we are working on a new login procedure.

When migrating the old forums over to our new forums we were unable to retain the identity of the authors, so the old posts will show up as "anonymous". All NEW posts will show up credited to their authors. So please participate and share knowledge just as you have in the past.

You must log in if you are an existing user or register if you are a new user in order to contribute to the discussions.

Discussion Forums - The Hendrix Group
HomeHomeDiscussionsDiscussionsMaterial Select...Material Select...Crevice Corrosion of AL6XNCrevice Corrosion of AL6XN
Previous
 
Next
New Post
6/14/2006 9:00 AM
 
User is offline 
No Ranking

Joined: 1/1/0001
Posts: 0
I work at a power plant in Florida that draws seawater from the Gulf of Mexico for component cooling water. The system was orginally made of 316L and 317 material and it has now been changed to AL6XN. After less than 2 years of service I'm seeing crevice corrosion damage at flange faces. I recently disassembled a cyclone separator made of AL6XN for inspection. Two the 4 flanges had suffered from crevice corrosion and the other 2 had no damage. The only difference I can find between the flanges was the type of gasket used. Does anyone have experience with gaskets that provide better protection against crevice corrosion? One of the damaged flanges had a SBR rubber gasket and the other had a SBR rubber coated dielectric gasket with a cellulosic fiber embedded in phenolic resin core. One of the unaffected flanges had a SBR black rubber gasket and the other had a SBR rubber coated dielectric gasket with a core made of Kevlar fibers enbedded in a silicate type matrix. I understand that a tight crevice increases the propensity for crevice corrosion but I have to believe if the joint is leak tight, crevice corrosion will not occur. I'm thinking about using a Gortex gasket. Any suggestions?
 
New Post
6/16/2006 9:00 AM
 
User is offline 
No Ranking

Joined: 1/1/0001
Posts: 0
Jim, What type of AL6XN do you have, exactly....!!!?? See page 3 of this document: (where the new AL6XN-PLUS with enhanced crevice corrosion resistance is discussed). http://www.trent-tube.com/literature/pdf/AL-6XN_PDFs/AL-6XN_sourcebook.pdf Pages 15-17 of the sourcebook discuss the exact type of seawater corrosion you seem to be undergoing. Any seawater systems benefits from continuous circulation. Is the corrosion in a "non circulating" part of the piping system ? The history of this material is interesting.....It was originally developed for seawater applications when it was called "AL6".....then the "XN" got added with improved properties,.....new we have AL6XN-PLUS........ Stay tuned for "AL6XN Double Pluss-WHIZ-BANG-II"..!!???? Hope that this helps... Please complete this thread by telling us about your eventual fix for this problem. Regards -MJC
 
 Page 1 of 1
Previous
 
Next
HomeHomeDiscussionsDiscussionsMaterial Select...Material Select...Crevice Corrosion of AL6XNCrevice Corrosion of AL6XN


  

News

NEW! Calculation of Ammonium Salt Deposition Temperatures
With a little delay, our Calculation of Ammonium Salt Deposition Temperatures...read more
Sulfidic corrosion calculators NOW AVAILABLE
Our sulfidic corrosion calculators are now available at hghouston.com/calcula...read more

Stay Current

Sign up for our quarterly newsletter

covering updates on corrosion

Sign Up