Mig Welding 4130 chromoly

[Rich1973]

I have a millermatic 210 wire welder. I have built a couple of dune buggies with steel tubing.I am looking into building the next one with a chromoly frame. I have about 9 years welding experience with steel and stainless steel,but never chromoly.I would think Tig would be the preferred method,but all I have is my mig.

Is there a preferred gas mixture and is there a special wire that I will need to weld 4130 chromoly?What type of problems should I expect with using the mig process to weld chromoly?

Thanks,Rich1973

[dyn88]

uncoated er80

[aametalmaster]

Rich, Miller sent me a Power Click issue that covers this, i can't find it right away. Maybe Andy has one handy...Bob

[Paul Seaman]

Rich:
Welcome Aboard, I have done some of this with ER80S6 with c25 gas. The real issue is in the HAZ{heat affected zone} the weld will have a larger HAZ with mig than tig. Mig will fuse the materials and perform well. The trick is if you ever try to get sanctioning body approval for a racing version, probably wont get it. NHRA,WOO, and many other racing sanction bodys require Tig welded chassis. Hope this helps.
Peace,