×
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

Welded 316L part, NACE MR0175 Compliancy

Welded 316L part, NACE MR0175 Compliancy

Welded 316L part, NACE MR0175 Compliancy

(OP)
Hi everyone.

Sorry if this looks like a duplicate subject; I know there are lots of other threads regarding NACE MR0175, welding and PWHT requirements, but I couldn't find a clear answer to my problem in any of them.

Here's the deal: we are manufacturing 316L thermowells which are to be compliant with NACE MR0175. The raw materials are NACE certified, but they need to go through some fabrication procedures such as welding and turning.

As for welding, the standard only states that the hardness of weldment, HAZ, etc. needs to be lower than 22 HRC and that the carbon content needs to be < 0.03%. But it doesn't say (as it does with martensitic stainless steels, which need to go through a PWHT at 621 deg. C) how to achieve this hardness value. Is it enough to conduct a sample section test as instructed by ISO 15156, after our as-usual PWHT?

Also, will the turning induce any non-negligible cold work on the part? How about tapping?

Thanks!

RE: Welded 316L part, NACE MR0175 Compliancy

(OP)
Double also, does the whole part needs to be NACE compliant or just the wetted sections?

RE: Welded 316L part, NACE MR0175 Compliancy

Austenitic stainless steels are not usually subject to PWHT, hence ISO 15156 doesn't really need to address it since the PWHT would have to be a solution anneal or anneal anyway.  It just becomes a question of qualifying the welding procedure with a hardness test as directed.  You will note that A.1.5.3 of Part 3 regards turning and threading as normal machining operations with no restrictions. As to how much of the part needs to comply with ISO 15156, that would be down to the end user to specify.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04
 

RE: Welded 316L part, NACE MR0175 Compliancy

(OP)
Thank you so much for your answer SJones.

So, if the hardness test of the sample(s) turn out to be OK, there will be NO need for solution annealing the whole part again, right?

RE: Welded 316L part, NACE MR0175 Compliancy

I worked in a sour facility in the 90's. During start-up we had numerous 316L to A333 Gr. 6 thermowell welds fail due to stress corrosion cracking. We changed them all to allow for PWHT. I don't recall what material was used but will try to find out.

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