Now, this isn't exactly high tech but the way we used to do them is heat them EVENLY to a bright cherry red, douse them in oil (leave them in until they are cool) and then heat them just to a dark red and bury them in fine sand until completely cooled.
The secret is to cool them SLOWLY. Getting the color (temp) right is something that comes with practice. One guy I knew used to pack his in clay, then wrap it in thin sheet steel and bake it for about three days. I didn't like this method for blades as they come out so hard as to be VERY difficult to sharpen. It does however, work great for hardening new frizzens for flint locks.
I'm sure there is a newfangled method out there that will be easier, but I doubt the results will beat the old method. Also, there's really nothing like knowing you can harden steel with just a torch, a can of oil, and some sand.
Good luck, and keep me posted on the progress.