| Chaucer, Spenser, Shakespeare, Milton, Burns, Wordsworth, Keats, Shelley, Tennyson, Browning. ... Read more of TEN GREATEST ENGLISH POETS at Speaking Writing.com |  InformationalPrivacy |
Steel MakingRate Of CoolingAt the option of the manufacturer, the above treatment of gea... Sulphur SULPHUR is another element (symbol S) which is always found i... Carbon Steels For Different Tools All users of tool steels should carefully study the different... Carburizing Material The simplest carburizing substance is charcoal. It is also th... Corrosion This steel like any other steel when distorted by cold worki... Ebbw Vale And The Bessemer Process After his British Association address in August 1856, Besseme... Composition Of Transmission-gear Steel If the nickel content of this steel is eliminated, and the pe... Annealing Method Forgings which are too hard to machine are put in pots with ... Heating Of Manganese Steel Another form of heat-treating furnace is that which is used ... Hardening Steel is hardened by quenching from above the upper critical.... Temperatures To Use As soon as the temperature of the steel reaches 100 deg.C. (... Vanadium Vanadium has a very marked effect upon alloy steels rich in c... Calibration Of Pyrometer With Common Salt An easy and convenient method for standardization and one whi... Piston Pin The piston pin on an aviation engine must possess maximum res... Silicon Silicon prevents, to a large extent, defects such as gas bubb... Introduction Of Carbon The matter to which these notes are primarily directed is the... Lathe And Planer Tools FORGING.--Gently warm the steel to remove any chill, is parti... Making Steel Balls Steel balls are made from rods or coils according to size, st... Annealing There is no mystery or secret about the proper annealing of d... Non-shrinking Oil-hardening Steels Certain steels have a very low rate of expansion and contract... |
The Modern Hardening RoomCategory: HARDENING CARBON STEEL FOR TOOLS A hardening room of today means a very different place from the dirty, dark smithshop in the corner with the open coal forge. There, when we wanted to be somewhat particular, we sometimes shoveled the coal cinders to one side and piled a great pile of charcoal on the forge. We now have a complete equipment; a gas- or oil-heating furnace, good running water, several sizes of lead pots, and an oil tank large enough to hold a barrel of oil. By running water, we mean a large tank with overflow pipes giving a constant supply. The ordinary hardening room equipment should consist of: Gas or oil muffle furnace for hardening. Gas or oil forge furnace. A good size gas or oil furnace for annealing and case-hardening. A gas or oil furnace to hold lead pots. Oil tempering tank, gas- or oil-heated. Pressure blower. Large oil tank to hold at least a barrel of oil. Big water tank with screen trays connected with large pipe from bottom with overflow. Straightening press. The furnace should be connected with pyrometers and tempering tank with a thermometer. Beside all this you need a good man. It does not make much difference how completely the hardening department is fitted up, if you expect good work, a small percentage of loss and to be able to tackle anything that comes along, you must have a good man, one who understands the difference between low- and high-carbon steel, who knows when particular care must be exercised on particular work. In other words, a man who knows how his work should be done, and has the intelligence to follow directions on treatments of steel on which he has had no experience. Jewelers' tools, especially for silversmith's work, probably have to stand the greatest punishment of any all-steel tools and to make a spoon die so hard that it will not sink under a blow from an 1,800-lb. hammer with a 4-ft. drop, and still not crack, demands careful treatment. To harden such dies, first cover the impression on the die with paste made from bone dust or lampblack and oil. Place face down in an iron box partly filled with crushed charcoal, leaving back of die uncovered so that the heat can be seen at all times. Heat slowly in furnace to a good cherry red. The heat depends on the quality and the analysis of steel and the recommended actions of the steel maker should be carefully followed. When withdrawn from the fire the die should be quenched as shown in Fig. 80 with the face of die down and the back a short distance out of the water. When the back is black, immerse all over. If such a tank is not at hand, it would pay to rig one up at once, although a barrel of brine may be used, or the back of the die may be first immersed to a depth of about 1/2 in. When the piece is immersed, hold die on an angle as in Fig. 81. This is for the purpose of expelling all steam bubbles as they form in contact with hot steel. We are aware of the fact that a great many toolmakers in jewelry shops still cling to the overhead bath, as in Fig. 82, but more broken pieces and more dies with soft spots are due to this method than to all the others combined, as the water strikes one spot in force, contracting the surface so much faster than the rest of the die that the results are the same as if an uneven heating had been given the steel. Next: Take Time For Hardening Previous: Hardening Carbon Steel For Tools
Viewed 920 |
||||||||||||||||||||
