Carburization.PDFVIP

CARBURIZATION The temper of Iron for Files It must be made of the best Steel, and excellently tempered, that it may polish, and fit other iron as it should be: Take Ox hoofs, and put them into an Oven to dry, that they may be powdered fine: mingle well one part of this with as much common Salt, beaten Glas, and Chimney-soot, and beat them together, and lay them up for your use in a wooden Vessel hanging in the Smoak; for the Salt will melt with any moisture of the place or Air. The powder being prepared, make your iron like to a file: then cut it checquerwise, and crossways, with a sharp edged tool: having made the Iron tender and soft, as I said, then make an Iron chest to lay up your files in, and put them into it, strewing on the powders by course, that they may be covered all over: then put on the cover, and lute well the chinks with clay and straw, that the smoak of the powder may not breath out; and then lay a heap of burning coals all over it, that it may be red-hot about an hour: when you think the powder to be burnt and consumed, take the chest out from the coals with Iron pinchers, and plunge the files into very cold water, and so they will become extremely hard. This is the usual temper for files; for we fear not if the files should be wrested by cold waters. But I shall teach you to temper them excellently G. B. Della Porta, 1589, Sources for the History of the Science of Steel 1532— 1786, Ed. Cyril Stanley Smith Carburizing is one of the most commonly performed steel heat treatments. For perhaps three thousand years it was performed by packing the low carbon wrought iron parts in charcoal, then raising the temperature of the pack to red heat for several hours. The entire pack, charcoal and all, was then dumped into water to quench it. The surface became very hard, while the interior