Question: High Strength Weld Procedure for 4330?

[Fairbanks]

Greetings All,

I am new here and very happy to have found this forum.

I need to weld 1.25 inch O.D. threaded couplings to 1.25 inch O.D., 0.12 inch wall thickness pipe. Both pipe and couplings are 4330. The finished sections will be screwed together to form a drilling rod that will be used for under ground drilling work. It will be rotating at approximately 4,000 RPM and subject to both compressive and bending stress.

I need to design a weld procedure for the coupling to pipe attachment. Could anyone guide me to a book or paper that might help?

Thanks in Advance!

Fairbanks

 

[metengr]

It appears that you will be using a fillet weld to ensure the threaded couplings remain secured after tightening. The main thing is you don't want to seal (fillet) weld over any exposed threads. Based on limited information you provided, I don't see the seal weld being needed for structural load-carrying purposes only to prevent the threaded couplings from loosening in service. If you have a different concept for the weld, please indicate as such.

4330 is weldable with deep hardening capability. So, you need to use a 400 deg F preheat. I would consider an E8018 B2 filler metal with a low hydrogen designator - H4.

Since you don't have a weld procedure you can try and have a mock-up and let the welder become familiar with technique. Generate a weld procedure by using a sketch of the weld joint and add requirements for cleaning, preheat, and welding process with voltage and amperage settings. This is rudimentary but can be effective for your basic needs.

 

[CoryPad]

I would consider friction welding.