×
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

Delamination on A106 GR B

Delamination on A106 GR B

Delamination on A106 GR B

(OP)
I have been recently asked to find out why delamination on outside surface of 18" sch 80 A106 GR B pipe after post-weld heat treatment at field shop as per NACE MR 0175 was made.
I saw the photos of pipe taken, of which lamination depth  are ranged from 0.08" to 0.12".
I looked into MTR supplied by steel maker and heat treatment report but I didn't find any error and/problems on these documents
so finally I have checked minimum required wall thickness to see if this pipe remains sufficient thickness to meet design conditions even though cutting delaminated area.
Foutunately, it seems this pipe is available.
Have you guys experieced this kind of problem before?
I would apprecate if someone give me your story and the reason why you got to know.
 

RE: Delamination on A106 GR B

Sounds like lamellar tearing in the pipe base metal. Yes, I have seen this before.

The orientation of inclusions were aligned such that during welding, residual stresses coupled with any hydrogen introduced during welding process created a preferred fracture path after PWHT. Check the sulfur content of the steel, and elevate the preheat during repair.

RE: Delamination on A106 GR B

(OP)




Hello metenger,

The delamination occurred in pipe is not weld metal but the surface of outside.

I can figure it out if this was happend in weld metal.

I am not sure but this problem could be related to heat treatment because the laminated area was covered when post-weld heat treatment on welding area.

What about your idea?

Thanks









RE: Delamination on A106 GR B

Can you post an example of the pictures of the laminations so we can look at it? Use http://flypicture.com/ or similar link

RE: Delamination on A106 GR B

106coral;
How far away was the weld that required PWHT from the damaged area? If you have a picture, can you post it on the web site below?

One other possibility - check to see if a local weld repair was performed by the mill in this exact location by removing a sample capturing the damaged area of the pipe and performing a metallographic examination.


http://flypicture.com/

RE: Delamination on A106 GR B

(OP)
How can I do to upload some pictures on this forum?

RE: Delamination on A106 GR B

106coral to upload pictures use a web site like

 http://www.flypicture.com

When you go to that web site it will walk you through the process.

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