×
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 50ksi Structural to Q&T Plate

Welding 50ksi Structural to Q&T Plate

Welding 50ksi Structural to Q&T Plate

(OP)
I am trying to redesign an existing piece of outdoor structural equipment and bring it in line with code.  I have two options to rework a deficiency where a square HSS member joins to a plate with a fillet weld around the square HSS:

1.  Replace an 1 1/4" A36 plate with a ~80 ksi plate.  Likely will have to a quenched and tempered plate to get that strength.  

Q:  How difficult is it to weld a 50ksi plain carbon structural steel to a 80+ ksi Q&T plate?  I suspect a detailed weld procedure (preheat, rod selection, etc) will be required.

2.  Upgrade to a 50ksi plate but it will still be plain carbon steel.  To get the increased strength add gussets/braces where required.  Can continue to use the existing 7018 rods we are currently using.  Will be heavier but "simpler" and maybe more cost effective in the end.

I suspect most will pick option 2 as the preferred option.

RE: Welding 50ksi Structural to Q&T Plate

Quote:

Q:  How difficult is it to weld a 50ksi plain carbon structural steel to a 80+ ksi Q&T plate?  I suspect a detailed weld procedure (preheat, rod selection, etc) will be required.

It is not difficult to weld carbon steel (A 36) to a low alloy quenched and tempered steel plate, certain precautions are required. Preheat will need to be reduced to 150 deg F or less, and the interpass temeprature would need to remain at or below 350 deg F (this is critical). Because you are dealing with a base material that has been heat treated by quenching and tempering, post weld heat treatment should not be performed.

I would suggest a E9018M filler metal if you are using the SMAW process. This filler metal is typically used for welding ASTM A 514 low alloy steel plate that is quenched and tempered to itself or to a lesser grade carbon steel.

I would strongly suggest you qualify a welding procedure for this base material combination.

item 2; yes.

RE: Welding 50ksi Structural to Q&T Plate

(OP)
Thank you for the help by sharing your knowledge.  Very helpful.

RE: Welding 50ksi Structural to Q&T Plate

I suppose it's hard to get A 709 HPS 70W in small quantities, but it's considered to be about as weldable as A 572 Gr. 50 steel if you can get your hands on some.  Welding it to the Gr. 50, you'd use the same electrode you always use, but you'd need to use some preheat.

Hg

Eng-Tips policies:  FAQ731-376: Eng-Tips.com Forum Policies

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