×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

316L in swimming pool environment

316L in swimming pool environment

316L in swimming pool environment

(OP)
When we make pool equipment like pool ladders other types of things we use 316L bright polished tube. Then after a time it looks like it's going rusty we think it's the chlorine that's causing the problem is there anyway of stopping it with something. We clean them down but it seems to happen around welds or slight mucky areas rough places. It would be nice if there is a simple solution.

RE: 316L in swimming pool environment

Are you pickling after fabrication?
I suspect that a lot or this is related to small imbedded particles of iron.
These could come from being touched by a wrench or set down on a steel surface.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: 316L in swimming pool environment

There are number of weak acid (generally phosphoric or citric) solutions that will remove iron contaminants from the surface.
Be sure to only use stainless steel wire brushes that have never been in contact with carbon & low alloy steels to clean welded areas. Abrasive polishing with appropriate abrasives (also never used on carbon & low alloy steels are also effective.
What is the heat tint color after welding? You may need to pickle depending on color.

RE: 316L in swimming pool environment

Any weld heat tint, even a light straw color should be pickled.
If you use a wire brush or abrasive (as described above) you must passivate afterwards.
There are citric and/or phosphoric acid passivation treatments.
They must be done warm and they take hours.
A room temp dip in 25% Nitric acid will do the same in 5 min.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: 316L in swimming pool environment

(OP)
Thanks for the replys we don't use wire brushes to clean the surfaces they get cleaned using polishing equipment like mops polishing compounds. Then wipe down with rags and stainless cleaners.

RE: 316L in swimming pool environment

But without passivation the microscopic particles from the polishing that have been imbedded in the surface will be a source for corrosion initiation.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: 316L in swimming pool environment

Tell the kids to stop spalshing around so much, it increases the dissolved oxygen in the water.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

RE: 316L in swimming pool environment

Parts that are regularly wetted should never rust.
There is a reason why you are not allowed to use SS hardware overhead in pools.
Because it will fail and things will fall down.
Where it can't get rinsed the chloramines collect and eventually CSCC will cause failures, even at room temp.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources