mig or flux cored 4130

[pedro]

Hi all.
Can I use flux cored self-shield wire to weld 1.5" x .065-.095 4130 chrome molly tube?
Can I get a satisfactory weld?
What type of self shield wire can I use.

Thank you.
Pedro

[wrench3047]

I'm not sure about crome moly, but I've welded sheet about that thickness at the way up to 1/8 with flux core and other that the spatter and flux residue on the bead it fused the metal just fine. Even with destructive testing. I was using .030 flux core and it took a little to much juice to run the wire than it would have took to weld the .065 metal so I had to play with the trigger alot to prevent burn thru. I don't think anyone makes fluxcore any smaller than that.

[pedro]

Thanks wrench3047.
For me is more easy to weld using flux core beacuse I can look more accurate to the molting pod and with mig is kind of more dificult, I am going to build a space frame type of sports racer car, I have some experience on flux core welding on mild steel roll cage with satisfactory welds but with no rollover testing yet, I now that with mig you can have better welds, I am going to try both on chrome molly
If anyone has more opinions, please reply.

Thanks
Pedro K.

[Canuck]

I don't think the flux core would be good idea to use with the 4130. If at all possible it should be TIG welded but if you have the capability to MIG weld it than you should do that. Use an Er80-s6 wire and 75/25 gas. The flux core dose not have the tensile strenght or the mechanical properties tho make structuraly sound weld on 4130 steel. If any has any other opinions the please speak up.

[Paul Seaman]

Yes you can get fusion but it wont pass the technical inspection for any normal sanctioning body in racing. The tensil strength should be fine but the real worry will be HAZ{ heat affected zone}, the HAZ will be much larger than a similar size weld in tig. The less HAZ the more of the tubing's strength that is retained, which is the point. I have done it in Flux core, mig and tig. Tig is the best and flux core will be the worst of the 3 but its better than stick!

Weld well,

[aametalmaster]

Pedro, Go to the Miller welds home page. on the toolbar at the top click on EDUCATION then on POWER CLICK, on the left side look for the ARCHIVES. You need ISSUE 7,2003. You can't get a better explaination than this. Hope this helps...Bob

[pedro]

Thank you guys, you all really gave me exellents coments, the miller education issues are very good too, I will go mig and start making my savings for a econotig.

Thanks all for your'e time.

Pedro k.