On 04/09/2020 22:15, Peter Hill wrote:
On 04/09/2020 21:04, Cursitor Doom wrote:
Gentlemen,

I've run out of the ideal 90:10 mix of argon and CO2 for mild steel
and was wondering if Nitrogen could be pressed into service as an
expedient, given how long it takes for gas to be delivered currently.
I have a nearly full half-size cylinder of pure nitrogen and it would
be handy to say the least if it would make a workable substitute as an
inert gas.
Any thoughts?

CD


Nitrogen is used as a blanketing gas on back of stainless steel welds.
This site says it won't work on mild steel.
https://weldingpros.net/types-of-welding-gases/

As Brian implies, nitrides in steels change the mechanical properties.
I'm not surprised that professionals don't recommend it on mild steel,
but surely you have nothing to lose by doing some trials on dummy
specimens. It all depends on how critical your welds are.