OFN (oxygen free nitrogen) for mig welding?

[jayrs]

I've never thought of using it for mig welding before, and cant find anything about OFN being used for mig welding (so im assuming its rubbish??) , but im just wondering if anyone has tried it, and why it cant be/isn't used?

reason i ask, i have and use OFN all the time, for pressure testing and for purging when brazing (as im a refrigeration engineer), and if i ran out of Co2 at any point and needed to mig weld before i could get some more Co2, could i use the OFN?

i guess i should just try it and see, but im interested to know what people have to say about it.

 

[shenion]

No, nitrogen is one of the main things the shield gas is keeping out of the weld.

 

[jayrs]

ah right fair play, i wont be using that then lol.
i'll get another co2 off my mate i think to keep as a spare

 

[Omniata]

No, nitrogen is one of the main things the shield gas is keeping out of the weld.

It adds nitrogen to the weld and causes "Nitrogen embrittlement", ie: it makes the weld somewhat porous and weak

 

[Hitch]

A cylinder full may be useful if you have a laser cutter kicking around in the garage.
Not a lot of use for Mig though.

 

[jayrs]

i dont want any weak welds, so thats that, wont be using it then lol

no laser cutter, what about a plasmer cutter? ive thought about getting one of them before

 

[Wozzaaah]

Plasma cutters just use compressed air.

 

[Omniata]

Can be a bit hit and miss with pure Nitrogen, the Oxygen found in air is usually needed to generate enough heat to blow the metal out with the Nitrogen...

Nitrogen isn't particularly easy to ionise and you'd have to grind the edges back thoroughly after cutting...

 

[jayrs]

ah thats ok, i got a compressor which will do that.


i wont bother with the OFN then, i'll just stick to using for what i use it for now, on frige and AC

 

[Hitch]

Big cnc plasma jobbies also use nitrogen, i doubt its has any benefit through a handheld type for general purpose use, not much as cheap as compressed air either.

 

[jayrs]

ah, i see, a compressor wont be man enough for a plasma then.

i dont pay for the OFN as its compnay stuff, as long as i dont take the mick (like loads of bottles), there happy for me to use it for what ever

 

[Hitch]

The cylinder gases are used to benefit the quality of cut.
Compressors are used for most handheld plasmas

 

[jayrs]

hmm, thats handy to know cheers.
if i will get one or not i dont know, but its always hand to know these things

 

[hotrodder]

Only electric welding related use i can think of for nitrogen is as a cheaper alternative to argon for purging although applications are limited. Stainless is the only one that comes to mind.

Nitrogen is a strong austenite former. As i understand it, it's only (or at least most) soluble in stainless in it's monatomic form (arc energy can dissociate N2) and can be used to purge many of the stainless alloys with closed root joints and/or when corrosion resistance isn't critical