×
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

Welding on B7 material
2

Welding on B7 material

Welding on B7 material

(OP)
We recently discovered a supplier had substituted B7 studs in place of the SA36 we ordered. (a no charge "upgrade") Some of these B7 studs got welded to SA516-70 plate as a lifting device (GMAW ER70S-6). I know that ASME does not recognize B7 as a weldable material, but this is not an ASME Code weld. It just needs to work. I am not concerned with the diminished tensile strength of the stud materials as it is not under high load. Perhaps 500 pounds on a 1" stud.

The question I have is, are these welds mechanically sound? Or is the B7 so hard that it will simply crack at the heat affected zone under impact? Or...???

Many of them are in the field and replacement would be difficult to replace.

Thanks

RE: Welding on B7 material

atomicbob, I'd say the B7 has a good chance of cracking. People have gotten hurt doing this.

You said 1" stud, but how much weld?

Can you NDE 'em all?

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

RE: Welding on B7 material

I wouldn't risk it for a lifting device. B7 is pretty dang hardenable.

RE: Welding on B7 material

(OP)
It is welded with a simple 1/4-3/8" fillet. Going forward we won't be using it. We are trying to assess the viability/necessity of reworking scores of units scattered over the globe.

RE: Welding on B7 material

Understood. Should be enough weld for the load if its sound.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

RE: Welding on B7 material

(OP)
Thanks. We will do some tests in house...weld some on and bash them around, see if we have any failures. I was just curious if welding turns B7 to glass, etc. nosmiley

RE: Welding on B7 material

atomicbob, let us know how it goes :)

The problem with sloppy work is that the supply FAR EXCEEDS the demand

RE: Welding on B7 material

You should perform surface NDT (like wet fluorescent MT)to at least ensure no cracks from welding, this is a MINIMUM requirement.

RE: Welding on B7 material

Welding B7 won't turn it to glass, but it could produce cracks and a microstructure that is similar to glass (brittle, unstable crack propagation under stress). Extreme caution is warranted.

RE: Welding on B7 material

Also perform your MT test after about 48 hours in case delayed cracking occurs. With GMAW, the weld metal and B7 HAZ will be quite hard. Assuming an Argon CO2 mix hydrogen embrittlement (cracking) is quite likely. We used to make this weld with nickel base filler metals and a 400F Preheat with great success.

RE: Welding on B7 material

This is just a threaded stud fillet welded to whatever it is you're lifting?


Does anyone actually feel comfortable that WFMT will accurately be able to find an indication in a 1" thread root? I've never tried, but I can't imagine it not immediately lighting everything up...

RE: Welding on B7 material

"Scattered over the globe..."

Be sure to "bash them around" at minimum ambient temperatures.

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