Heat treating question

[Acer Saccharum]

I have a piece of 0-1 tool steel with some delicate engraving on it. I wish to harden this without developing much oxidation scale. Any scale will ruin the engraving. Can I heat this piece in a crucible surrounded with charcoal, like I am case hardening? I know there is stainless foil toolwrap, but I don't have any of that.

It's a block, 3/4 thick, x 1 1/4" square.


This is the project. the end result will be a steel stamp which I will use to stamp the little gold insert in the jaeger barrel. This is a positive image, where the goat is engraved in low relief. I will harden this image, then press a soft punch onto this image, forming a negative cavity on the end of my new punch. while that new punch is still soft, I will shape it around the goat image, add a border, maybe some horizontal line patterns. Then it will be ready to punch the gold barrel disc. Goat is about 5/16 long.

[Robby]

 Acer, I'm not sure, but don't smithies use borox on sides they plan to fuse weld, for the purpose of preventing oxidation scale. Maybe covering the side you want to protect with borax would keep it in tact.
  Robby

[rich pierce]

If the engraving was of a fish or a snake, not an old goat, the scale could be a good thing.   

[LRB]

  Acer, I use PBC powder from Brownell's when heat treating blades. The steel is heated to 600°, then the powder is sprinkled on. It immediately melts and coats the steel. From that point the coating will prevent decarb, and surface oxidation. After heat treat, what doesnt come off in the quench, practically falls off in boiling water. The steel will be clean, but gray in color. The PBC powder is basically boron, and has no known permanent health hazzards, but it can give some a shortness of breath until they are out of contact with it. I use it with an exhaust fan, but have never had a problem. The foil would be another way, but it has to be removed before the quench, so that could get tricky. The clay coating many knifemakers use might also work, but I have no info on exactly what the stuff is.

[Metalshaper]

Acer,

 plain old boric acid!!< poor man's PBC powder  >  heat the part to about 300 or so,  and sprinkle it on. it will melt and fuse to the surface.
bring it on up to temp and quench as normal! Boric comes off the part and leaves it hard and with a soft greyish appearance.

at least its work for me in my blacksmithing?? 

Respect Always
Metalshaper

[Acer Saccharum]

Thanks, guys. I have some acid. Boric, that is. I will try some on a scrap, and see how it works.

i don't have a heat treat furnace, only BBQ or oxyacetylene. I am thinking the charcoal fire would be kinder to the steel than the oxy.

regards, Tom

[jerrywh]

The deoxidizing powders might work on what you are doing and the stainless wrap also. Boric acid or borax will leave some slight graining or very small pits in the metal. I harden some extremely fine engraved pieces and the only fool proof way is to charcoal pack. Charcoal packing will even protect portrait engraving. All of the very fine engraving on modern fire arms when hardened are done in charcoal packs. The stamp you made is actually not that critical. You could just heat it with a real rich oxyacetylene flame. The rich flame will not oxidize it.

[davec2]

Acer,

This is response is not about heat treating, but another option for making a punch.  If you can find a local shop that does EDM, get a small piece of the graphite they use for tools.  Carve the graphite into the form you want the gold to be when it is punched.  As I am sure you know, the graphite carves really easily with a graver.  Take the graphite tool back to the EDM shop and have them burn it into a hardened tool blank - I use various lathe tool blanks.  It only takes a few minutes of EDM time since the tool is only burned into the tool blank 0.010" or so.  Makes a very hard, well finished, long lasting tool.

[Acer Saccharum]

It's tuna fish for lunch, and save the can for packing the part in charcoal. Thanks, Jerry.

With foil, I have to get some foil, and then figure out how to un wrap it while it's so hot. It would be like playing 'Rambo hot potato'.

Davec, I like your stamp. I have some graphite, and I will save that for future projects. By the way, there is a company Sparks Stamps, in Long Island City, NY, who scans your art, cuts it on graphite, and burns it for you on HSS tool bits. Pretty reasonable.