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Intro: I have watched one too many blacksmithing videos and now I have a question: is it possible to forge steel (either just reshape or "forge-weld") inside a no-oxygen environment?

Scenario: considering the amount of material that turns into iron oxide during the forging process, would it be possible (or plausible) to fill a room with some non reactive noble gas (maybe helium or neon) and proceed to forge inside this room? Or would it be possible to forge in a complete vacuum?

If any of these two options are possible, what are the hindrances and requirements?

Extra info: I am not from the chemistry area and I haven't studied chemistry in years. I took a look at some old textbooks of mine and also did some research on on Google but did not find anything specific to this question. This is purely out of curiosity, and since I don't know how reddit works (therefore can't do a more relaxed inquiry there) , I thought it was not a bad idea to ask here.

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    $\begingroup$ Look at it this way: why bother about iron turning into oxide? Because it means lost money? Well, helium costs money too, and a good deal more than iron. Other than that, sure, why not. $\endgroup$
    – Ivan Neretin
    May 18 '18 at 16:45
  • $\begingroup$ Absolutely true. I just wanted to know if it was possible, or if there are any other possible limitations. Not so much for the loss of material and costs indeed. $\endgroup$
    – DGMS89
    May 18 '18 at 16:58
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    $\begingroup$ Yes it is possible, and in fact it is done when you weld Al or Ti. But with iron it is just not worth the effort. $\endgroup$
    – Ivan Neretin
    May 18 '18 at 17:04
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    $\begingroup$ Removing O2 will yield a steel that is different from one made via traditional methods - see below. Also, you can't have a combustion process delivering the heat for the forging if you do not use O2 at all. britannica.com/technology/steel/Basic-oxygen-steelmaking $\endgroup$
    – J. Ari
    May 18 '18 at 18:31
  • $\begingroup$ Yes, but would it be possible to use electric induction to heat up the steel? Would that have any impact on the surrounding gas? (I believe oxigen would ionizer, but I'm not sure either how would that impact the result, nor if it would happen to a noble gas) $\endgroup$
    – DGMS89
    May 18 '18 at 19:03
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It is possible to forge iron in a low atmosphere environment, but it isn't worth it because there are few if any benefits to doing so.

This isn't true for some other metals, though, or even for some specialist steels. In many other metals and alloys the presence of oxygen or water vapour has a very bad effect on the quality of welds. But the common way to exclude air from these systems is to use an apparatus that flows some inert gas around the spot being welded rather than to fill the room with an inert gas. Some examples are given here.

This is mainly worth doing for many specialist aluminium, copper and titanium alloys where the metals are oxidised more easily than typical irons or steels and effect of impurities in the welds is much larger. It isn't as simple as just having an inert gas blanket though, as this brochure for commonly used gas mixtures shows.

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  • $\begingroup$ "Stick" welding of steel is still very common; no gas except what is generated by the flux coating . MIG is common for steel ; Two methods - solid wire with gas and flux cored without gas. And for heavy steel weldments - subarc uses flux with no addition of gas. $\endgroup$
    – blacksmith37
    May 19 '18 at 21:50
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A forge weld contains oxides, mostly iron, which reduce its mechanical properties. The extent of property loss depends on the amount and orientation of the oxides. Modern steel welding techniques shield the weld puddle from oxygen with fluxes and/or gas ( mostly CO2 ). One could make some expensive equipment to shield a forge weld from oxygen but it would be much more costly than other welding processes. Likewise , forging could be done in a protective atmosphere ; it would be very expensive and give no advantage other than saving a little surface steel. I think some forging operations for titanium use protective atmospheres because it is so expensive and will absorb O , N , and H from air ( at forging temperatures). And the various "blacksmith" programs are entertainment, not science or technology.

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I've wondered about this too. Not from a practical sense, but more of a "that would be kinda cool" perspective. For iron I'd go with nitrogen. All you'd be doing is flushing out the oxygen. (I'm not sure about other metals) I guess you'd have to use an induction forge to heat your material. You could just have some kind of basic breathing mask or tube supplying you with air, maybe even one just going outside of your enclosure. You'd just need to get enough oxygenated air to you to breathe comfortably. I don't think you'd need to seal out the nitrogen because it's 78% of our atmosphere anyway and not harmful to us. I would definitely make sure you had a quick and easy method of exit, or a way to just open the enclosure to outside air. Maybe some kind of dead-man switch so that if you became unconscious or incapacitated for any reason, the enclosure would automatically open to outside air. I'd also have that same switch controlling the induction forge so that it would shut off if you tripped the switch. I mean, like others have said, it's probably not worth the cost and effort, but I think it would be interesting to see if it meant you didn't need flux, and if it improved bonds when people forge weld billets from things like bicycle chains.

disclaimer: I'm not a blacksmith or a metallurgist. I'm just commenting because I like the question and I enjoy working it out in my head.

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