×
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

root cause for failure of bend test

root cause for failure of bend test

root cause for failure of bend test

(OP)
Hello,

what is possible root cause for failure of bend test from haz(crack parallel to weld seam).

bend sample taken from tranverse to weld seam in api 5l x52 material..

RE: root cause for failure of bend test

Hi

Please can you give a lot more information about the failure at present the failure could be a multitude of things of which the following list is not exhausted:-

Hydrogen embrittlement
weld porosity
lack of fusion
weld inclusions
incorrect post or pre heat treatment
incorrect filler material
incorrect settings of weld parameters

A picture of the failure also might help you get some proper answers

RE: root cause for failure of bend test

What was the welding process and welding filler metal used? If E7010, most likely hydrogen embrittlement.

RE: root cause for failure of bend test

Not enough information to provide an opinion. Have the sample examined or have a competent met lab evaluate the bend test failure.

RE: root cause for failure of bend test

Is this an ERW weld?

If so, you can rule out:
Hydrogen Embrittlement (if you have hydrogen problems, you have a base metal problem and the integrity of the weld isn't going to matter)
Weld Porosity (If there in porosity in an ERW weld, again, it's a base metal problem, not a welding problem)
Lack of Fusion (ERW is a non-fusion process; there is no fusion, so it can't be lacking)
Incorrect filler metal (as with the fusion; hard to have incorrect filler when there is no filler metal)

That leaves:
weld inclusions (could show up as hook-cracks; check silicon content and weld pressure)
incorrect pre/post heat (in particular normalizing of the weld seam and cooling afterward)
incorrect weld parameters
and, not mentioned
improperly prepared faying surfaces (dirty, contiminated, or unsuitable geometery).

rp

RE: root cause for failure of bend test

(OP)
thanks to all to give your presious openian..

we are using double side welding by tandam arc saw , woldwide used for manufacturing of line pipes as per api 5l LSAW PIPE.

before cut bend sample rt was clear,
pipe size: 18"X17.50mm
grade: api 5l x52mo

hardness come in haz area was max 200hv10

RE: root cause for failure of bend test

Thanks for the additional information. It could be lack of fusion from your original description. However, this is only a guess and you need to send it to a lab for root cause analysis.

RE: root cause for failure of bend test

The process is not low hydrogen plus acid based fluxes are often used plus preheating normally not done; hydrogen embrittlement remains a suspect. Was there appreciable mismatch (skewing) of the two sides (ID & OD) of the weld or were they symetrical?

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