Welding 4130 steel

[MinotJeep]

I'm pretty new to welding, but have done quite a bit of gas welding with the O/A torch, and feel pretty comfortable welding with it. I would like to try making something out of 4130 in the future, but have read that without stress-relieving the structure after it is welded -as in putting in an oven-, brittle welds will result. I found this information on a pirate 4x4 article ( www.pirate4x4.com/tech/billavista/PR-BV60/index1a.html ) and the author seems to know what he's talking about. Would this apply only with TIG welding, or would the wider HAZ with the torch help to normalize the weld areas? With all the gas welded aircraft fuselages out there that weren't stress-relieved, I find it hard to believe welding 4130 is a lost cause to someone without that kind of equipment.
-Matt

 

[BrettM]

chromoly was originally designed for O/A welding, go for it.

 

[biscuitboy87]

welding 4130 is done more with tig, but can be done with oxy/ace as well.
most books i have recommend er70-s6. the benifit to welding with the gas flame is that with the oxy/ace process one is apt to use more filler instead of less. the flame will possibly anneal the metal a bit too which depending on the intended use of the material is a good thing.

N