×
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

Crack in flange side when weld Flange CuNi to Tee CuNi

Crack in flange side when weld Flange CuNi to Tee CuNi

Crack in flange side when weld Flange CuNi to Tee CuNi

(OP)
Hi Friends,
Our project had serious problem. All weld joint between Pipe-CuNi to Flange-CuNi had defect crack in Flange side (Pipe side no problem). I would like give you some information to you give me advice:

Base: CuNi
Thickness: 7 mm
Welding Process: GTAW
Welding Consumable: ER CuNi, Lincoln LNT CuNi30
Backing Gas: 100% Agron
Preheat: Ambient (30 degree)
Max Interpass: 85 Degree
Heat input: 1-1.5 (Kj/mm)
PWHT: No
Parameter: 87-90 A, 10-13 V

RE: Crack in flange side when weld Flange CuNi to Tee CuNi

(OP)
sorry gents, I have misstake Tee replace Pipe

Pipe Tee-CuNi to Flange-CuNi

RE: Crack in flange side when weld Flange CuNi to Tee CuNi

Is this a corner groove weld or a butt weld? Is the flange cast or forged? Is the crack in the HAZ or at the fusion line?

RE: Crack in flange side when weld Flange CuNi to Tee CuNi

(OP)
Hi Gents,
This is weld neck flange. Attach picture for you refer



RE: Crack in flange side when weld Flange CuNi to Tee CuNi

With the very low heat input, LOF may be the actual flaw; however, if you have confirmed cracking, contaminants left on the Flange due to the heavy machining operation could be the problem or contaminants in the flange material itself could be the problem. A metallurgical examination of the defect and flange base material is recommended.

RE: Crack in flange side when weld Flange CuNi to Tee CuNi

LOF is a very strong possibility. Welding technique with CuNi is tricky, the filler metal sometimes appears to be pushed away from the joint. As I understand, the filler carries whatever heat is in the puddle away and actually quenches it resulting in LOF. Your welder wants to make sure he has a fully fluid puddle before dipping the rod into it, heat then needs to stay on long enough to melt the filler before pulling the rod. Something else that seems to help is to weld towards your ground whenever possible.

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