Chemistry - Forging steel inside a zero oxygen environment

Solution 1:

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.

Solution 2:

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.