Learn How to TIG Weld 4130 Tubing

Learn How to TIG Weld 4130 Tubing

4130 chromoly material is common in tubing applications,
especially in racing or areas where you want
higher strength steel. 4130 is a temperature-sensitive
base metal, so we have to take some
precautions when welding it. This is what 4130 looks
like when you get it. To prepare it for welding, we actually will grind the tubing, especially where we’re going to weld it. You can either use some Scotch-Brite or a sanding disc to prepare
the tubing for welding. You’ll want to grind off and remove this mill
scale off of the tubing, so that it doesn’t get
included in the weld puddle. Fit-up is also important when
working with 4130 chromoly. You want your fit-up extremely tight. Any gaps in that fit-up will case you to spend more time welding that area, causing more heat to be input to the 4130. Filler metals that I like to use for 4130 are the ER80S-D2 filler metal and a second choice would be the ER70S-2. Stay away from any of the stainless or stainless blended filler metals because the tensile strength is too high and ultimately, the weld area could crack. Another thing to keep in
mind when welding 4130 is to use a gas lens on your tig torch. The gas lens is going to give
you a much better gas flow and coverage of the weld area. When welding a standard T joint where it’s easy to get into that area, your tungsten could be fairly close to the weld joint area. Keeping your arc lengths
low is also a good way to prevent overheating of the 4130. Sometimes, that’s not possible. Sometimes, your weld joint is
a very tight included area, so getting into this area to
weld it presents a challenge. The gas lens, however,
does increase the gas flow, allowing you to pull
your tungsten out farther to get into this tighter area. Another thing you might want to do is increase your post-flow
times on your machine. The post flow is the
amount of gas coming out of the TIG torch after you
release the foot pedal. You’ll want to make sure
that you want to keep gas on the weld pedal for that
extended period of time as it’s cooling. Warning: Read and follow all labels
and the Owner’s Manual. If you’re interested in more videos on welding 4130 chromoly, check out Miller Welders on YouTube.

One thought on “Learn How to TIG Weld 4130 Tubing

  1. As an aircraft engineer and inspector I find there to be less problems with welds that were done with good old fashioned oxy-fuel welding as opposed to tig welding.

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