[steve-l]

I am looking for a recommendation for welding a con rod journal on a forged AISI 4140 crankshaft. This crank is a single throw unit with two main journals with two splined ends. I know that before welding, the crank must be annealed, as it has been induction hardened. I also know it must be preheated before welding and slowly cooled at 95 degrees C/per hour after to prevent cracking. After this, I understand the crank must be stress relieved at 625 C and cooled in still air. What I do not know is what welding process is best and what filler rod needs to be used. I would rather not weld up the main journals if I can prevent shaft distortion and oxidation, so what would be the best way to prevent oxidation of those sections during all the required furnace time. Once completed, this crank will be x-rayed before finishing, heat treated and nitrided. All advise here is welcome.

I

[Otto Nobedder]

That one's a little above my pay-grade...

I'd take that one directly to Jody, throught the "contact us" tab on the main page at www.weldingtipsandtricks.com

Be patient. This question will interest him, and he'll answer.

Steve S

[Alumike]

Crankshafts are usually welded by submreged arc process. Set up in a special "lathe". Either the chucks can be offset to rod journal stroke or the welding gun follows the journal. Filler material and flux are the manufacturer's secret.