This is my first attempt at pack carburizing. The part shown is a small grinding vise made from low carbon steel, here it has been packed in charcoal fragments within a covered steel container. The package was then heated to 950C ~(1750F) for 4 hours then quenched in water. The high heat is necessary for the absorption of carbon in the gamma range. One of the sides of the vise didn’t receive the same spectacular colours as on the opposing end, this resulted from longer exposure to the open air. In the future if I intend to solely harden the outside, its best to cool the parts to between the upper and lower critical temperature before quenching, so as to avoid a Bainite structure of the steel for a pure martensitic structure.
Some important notes.
-Ensure that the metal container doesn’t contact the electrified elements, and turn off the power while loading and unloading the container.
-Use natural charcoal, not briquettes as I did. Because the wax used as a binder will make excessive smoke and will blacken the inside of the oven.
-Ensure the ovens surrounding is well ventilated.
-Wear protective clothing, gloves, shoes and a face shield to guard against sparks and flames.
-Preheat the oven before inserting the container. The charcoal can produce carbon monoxide gas before the autoignition temperature of 600C ~(1100F). Having the oven walls preheated will help to ignite the gas before it escapes.
-Finally. Safety is your responsibility, along with the risk associated with fire and burning, the monoxide gas can be lethal.
Do this at your own risk, I will not be held responsible for any death or injury following the viewing of this video.
Post time: Jun-18-2017