×
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

4140 to cast steel preheat

4140 to cast steel preheat

4140 to cast steel preheat

(OP)
I have a gear that is made up of a cast steel center hub and a 4140(annealed) ring that the teeth wil be cut in post weld. (Flame hardened after machining) This is approximately 24" dia. and we will be welding a 1/4" fillet weld all around both sides with either FCAW (E71T) or GMAW (ER70S-6). The question is what should the preheat, interpass and postheat temperatures be? After postheat it will cool overnight to ambient and customer will pick up in the morning. My guess would be approximately 400 degree preheat. 600+ degree postheat (to diffuse Hydrogen) and cool as slowly as possible. I tacked the piece in place (at ambient) with GTAW and ER70S-2 and had cracking issues.    Any suggestions/ corrections you could offer would be very helpful.  

RE: 4140 to cast steel preheat

WelderCWI;
Your stated preheat and interpass temperatures are acceptable considering the sizes of the attachment welds. I would have the hub and rting preheated to 400 deg F and held at this temperature for 15 minutes before welding.

RE: 4140 to cast steel preheat

A higher preheat would not hurt. I had to go to 500F on 4140 castings (2" + thickness) to prevent cracking.

RE: 4140 to cast steel preheat

'Donut' shaped welds are the worst case for shrinkage stresses.  Use the higher preheat and heat the ENTIRE assembly.  Follow extreme moisture control practice for the filler and the part.  

You are using the correct filler metal.  Did the shop foreman (in his infinite engineering wisdom) not insist on a 'matching' filler metal?  ;)

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