Janicholson
05-22-2006 17:49:31
|
Re: Hardening Metal in reply to MAGMAN, 05-22-2006 13:51:22
|
|
Jon, There is no good way to do the task, As others indicate, carbon in the steel is the key. One point of carbon is .01%, or .0001 carbon. Mild non-hardenable steel is between 0 points of carbon, and about 10 points. It is almost pure iron. Low carbon Steel is between 10 points, and 30 points of carbon (SAE-1010) steel is iron with 10 points of carbon. Medium carbon steel has from 30 to 60 points of carbon. High carbon steel is from 60 to a max of 150 points, (equal to 1.5% carbon). Metal working files are made from 120-150 point carbon steel. That high range is as hard as steel can be made to be (assuming no other alloys are added, which is a whole other ball game and not in this discussion). Hardening is possible above 10 point, but not very hard, till the upper 50 point area is reached. Hardening requires some individual experimentation on the material to get it as hard as needed with out making it brittle. Brine quenching, water quenching, oil quenching, and other cooling methods are done from a critical temperature that causes a particular molecular size and carbon bonding to take place. These methods are to be found in college texts on metals. For rough purposes, on a shined up piece of 60 point steel sheet, when the material turns to a wheat straw looking gold color, it is at the correct temp to quench. The whole item must be heated to that temp uniformly. Fast movement with a propane/air torch will do it. Source of massive quantities can be found in metal banding used to bundle materials for shipping, some of it is superior material. If it is too hard to work, anneal it by heating to medium red, and then slow cooling by removing the torch slowly, and then putting it in ashes insulating it so it is soft. Shape it then heat treat it to the spring temper as above. I know this is long, but I think it is what you are looking for. Good luck, and good practice. JimN
|
|
|