Joining 4142 with EB welding

[Kulungi]

I am trying to join ASTM A514 or 4142 to its self by EB welding. I have questions
1.) Is it required to pre prior to welding and post heat after welding?
2.) If the pre is 450 deg F does it have to be 450 or in transering from the oven and parts are 375 deg F is that good enough?
3.) Post heating does it have to happen immediatly after turning off the beam or can tha parts cool to 200 deg F priot to heating up to 600 deg. F?
4.) I know this material is prone to cracking due to hardening at the weld joint. Should your heating be in the Vacuum chamber?

 

[metengr]

Kulungi;

(1) What is the thickness at the weld joint? This will determine your PWHT requirement. What is the original heat treatment of 4142?

(2) Your stated preheat requirement looks acceptable even with the drop in temperature to 375 deg F. I would try to shoot for 400 deg F minimum prior to EB welding.

(3) No, post weld heat treatment (PWHT) does not need to be performed immediately after welding.

4). No

 

[stanweld]

Defocussed beams can and have been used to provide preheating and post weld heating when welding 4142 alloy steel. Thickness at weld joint will determine if defocussed beams can be used - especially with regard to PWHT.

 

[Kulungi]

Is the defocused beam on the part weld joint or just on an area that is going to be further machined. I assume this heats the entire part. I would suspect that a TC would have to be attached to the part near the weld joint. The parts in 22" long with 1/2 depth of weld with 100% penetration. If your heating one end does the hole part to heat this way or would your have to use the beam over the entire part? Maybe just in specific areas?

 

[stanweld]

Defocussed beams are used to preheat or stress relieve the joint area - not the entire part.