I've been thinking about this for a few years....but never pursued the answers...

During heat treating, carbon is proned to be removed from the steel in the pressence of oxygen. ...So we play games in an attempt to keep the precious steel away from free O's in the furnace...such as inert atmospheres, vacumns, salt baths, foil wraps, cumbustion parameters...etc. In some cases, we can even carbon enrich the surface of a low carbon steel if we generate a carbon rich atmosphere...ie, case hardening, carbo-nitriding,..etc. Hence, it is fundamental that we can remove carbon from steel and we can put carbon in steel. (over generalized, but follow with me...)

Now, here is what I ponder. In a simple electric furnace with out inert gas, or vacumn can I control/prevent decarb by wrapping the work piece in a stainless foil wrap and inside the wrap, I pack an excess of carbonous material. The carbon material may be wood chips, coal, paper.etc...about anything that would normally burn. So when it is in the furnace the free oxygen inside the foil pack, would be consumed by the cumbustion of the packing material and hence, preserve the carbon in the steel. Once the oxygen is converted, the cumbustion would cease.

Does this make any sense?..The idea is to supply an excess (fuel rich) of carbon such that any free oxygen is converted to CO2 and H2O hence generating an inert atmosphere inside the foil pack.

As simple as this concept is, does anyone practice it? I've never seen it around tool and die shops.

Whatta you think?

Sincerely,
Rob

Rob, the insertion of a bit of (unprinted) grocery bag inside the foil wrapper is pretty common practice. I have used it for many blades, and in the last year or so, have deliberately included it with some, and omitted it with others. All I can tell you is that it doesn't seem to make any difference at all.

Keep in mind that I am dealing only with air hardening stainless steels.

Mike Norris swears that including it causes decarb on his stainless damascus. I don't know if there is a "real" answer, because there are some other variables. For example, you can squeeze out almost all of the air from a foil wrapper - or not.

My thought is that if you are holding a steel at or above critical for the amount of time it would take to decarb or to recarb, then it's too long. Keep in mind I am speaking of steels that are generally forged.
Most of the steels that require high temp, or long duration soaks would likely benifit from an inert atmosphere, just as insurance. On the other side of the coin, to "enrich" a piece of steel with carbon takes a VERY long soak at specific temps. With this the steel must be packed in a carbon rich material, and rarely exceeds more than a couple of thousandths in absorbsion depth (case hardening)