mig welding steam pipe

by John
(Little Neck, New York)

My question is … can I mig weld steam pipe? It is schedule 40 black iron pipe ranging from 3” to 8”. If so what kind of wire would be recommended? ER70 series or an inner shield, flux core type? What diameter/ gauge wire? And if a ER70 type wire can be used what gas type… straight Argon, C25 mix, straight CO2? If you can help me it would be greatly appreciated. Thank you
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jody here at welding tips and tricks....

pretty much all welding codes require extra qualification tests for using bare wire short circuit mig welding.

for flux core mig, you can get prequalified procedures from the American welding society.

the fact that they make you run more tests for mig is a clue. It definitely can be done, but needs to be proved out by qualifying the procedure.

to play it safe, flux core with shielding gas is probably the safest and most productive way.
.035 or .045 wire dual shield will give good results.

go to this link for parameters or buy the prequalified procedure from the AWS.
if you are doing code work, the prequalified welding procedure will be a cya for you.

http://www.millerwelds.com/resources/calculators/mig_flux_amperage_calculator.php