×
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

Cathodic Protection for 316 Stainless Steel

Cathodic Protection for 316 Stainless Steel

Cathodic Protection for 316 Stainless Steel

(OP)
Greetings

My question concerns the use of cathodic protection for a 316 stainless steel seawater screen.

I believe that any type of stainless steel will not need cathodic protection, as stainless steel in general is pretty resistant to corrosion.  

However, the screen will be submerged in seawater at all times.  I've read online that stainless steel structures in a "splash zone" will require cathodic protection.  I don't know if being submerged in seawater will facilitate the need for cathodic protection.

Any advice?  Thanks in advance.

RE: Cathodic Protection for 316 Stainless Steel

I don't know the actual recommendations for your application but we have CP on our carbon steel and 316 SS river water screens, both static and moving.

There are many ramifications to you proposal so if you could comeback with a little more information it would be great help in getting better advice.

What is it mounted to?

Is the intake flow all time?

Will you screen have any crevices?

RE: Cathodic Protection for 316 Stainless Steel

You may wish to Google for NiDI Reference Book 11 003 and download it (free) for review.

Steve Jones
Materials & Corrosion Engineer
http://www.pdo.co.om/pdoweb/

RE: Cathodic Protection for 316 Stainless Steel

316 is not considered resistant to crevice corrosion in seawater.  Some level of CP will be needed to achieve a reasonable life.
If you really want it to last in seawater without protection you will need to use a 6% Mo super-autenitic or a super-ferritic stainless.

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

RE: Cathodic Protection for 316 Stainless Steel

(OP)
unclesyd

1) The screen is mounted to a 316 stainless steel frame.  The bolts will also be 316 stainless steel.

2) Yes, seawater will be flowing all the time.

3) This is a brand new screen.  The space between the bolts and the frame could be possible crevices, but I'm not sure.

EdStainless

What is considered a reasonable life?  I do not have much experience so your input would be greatly appreciated.

Thank you everyone for your help.

RE: Cathodic Protection for 316 Stainless Steel

If this is a standard woven-wire screen, then every place that two wire overlap will form a crevice.

RE: Cathodic Protection for 316 Stainless Steel

316 is inadequate for immersion in seawater. 2205 would be the correct alloy if you want to avoid corrosion, except in crevices. If you can tolerate a little corrosion, use alloy 2003 from Allegheny.

Michael McGuire
http://stainlesssteelforengineers.blogspot.com/

RE: Cathodic Protection for 316 Stainless Steel

Hi,

Please can you advise, Instrument Unit (316 SS) being imerssed in ground water (high water table - wet season.  The units are going to be insulated (from cold).

What is the best solution for it:

1- Coated first with Epoxy coating, then wrap it with insulating materil.

   

RE: Cathodic Protection for 316 Stainless Steel

you can apply CP to the 316 SS, in sea water.

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