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Steel MakingSiliconSilicon prevents, to a large extent, defects such as gas bubb... Temperature Recording And Regulation Each furnace is equipped with pyrometers, but the reading an... Nickel Nickel may be considered as the toughest among the non-rare a... Typical Oil-fired Furnaces Several types of standard oil-fired furnaces are shown herew... Crucible Steel Crucible steel is still made by melting material in a clay or... Protective Screens For Furnaces Workmen needlessly exposed to the flames, heat and glare from... Hardening The forgings can be hardened by cooling in still air or quen... Detrimental Elements Sulphur and phosphorus are two elements known to be detrimen... Steel Can Be Worked Cold As noted above, steel can be worked cold, as in the case of ... Making Steel Balls Steel balls are made from rods or coils according to size, st... Restoring Overheated Steel The effect of heat treatment on overheated steel is shown gra... Cyanide Bath For Tool Steels All high-carbon tool steels are heated in a cyanide bath. Wi... Calibration Of Pyrometer With Common Salt An easy and convenient method for standardization and one whi... Chrome-nickel Steel Forging heat of chrome-nickel steel depends very largely on ... An Automatic Temperature Control Pyrometer Automatic temperature control instruments are similar to the ... Effect Of A Small Amount Of Copper In Medium-carbon Steel This shows the result of tests by C. R. Hayward and A. B. Joh... Oil-hardening Steel Heat slowly and uniformly to 1,450 deg.F. and forge thorough... Hardening High-speed Steels We will now take up the matter of hardening high-speed steels... Connecting Rods The material used for all connecting rods on the Liberty engi... Annealing Alloy Steel The term alloy steel, from the steel maker's point of view, r... |
Short Method Of TreatmentCategory: HEAT TREATMENT OF STEEL In the new method, the packed pots are run into the case-hardening furnaces, which are heated to 1,600 deg.F. On the insertion of the cold pots, the temperature naturally falls. The amount of this fall is dependent upon a number of variables, but it averages nearly 500 deg.F. as shown in the pyrometer chart, Fig. 61. The work and furnace must be brought to 1,600 deg.F. Within 2-1/2 hr.; otherwise, a longer time will be necessary to obtain the desired depth of case. On this work, the depth of case required is designated in thousandths, and on crown gears, the depth in 0.028 in. Having brought the work to a temperature of 1,600 deg.F. the depth of case mentioned can be obtained in about 5-1/2 hr. by maintaining this temperature. As stated before, at the top of each pot are several test pieces consisting of a whole scrap gear and several sections. After the pots have been heated at 1,600 deg.F. for about 5-1/4 hr., they are removed, and a scrap-section test-piece is quenched direct from the pot in mineral oil at not more than 100 deg.F. The end of a tooth of this is then ground and etched to ascertain the depth of case. As these test pieces are of exactly the same cross-section as the gears themselves, the carburizing action is similar. When the depth of case has been found from the etched test pieces to be satisfactory, the pots are removed. The iron ball then is dropped into the tube to seal the hole in the bottom of the pot; the cover and the tube are removed, and the gears quenched direct from the pot in mineral oil, which is kept at a temperature not higher than 100 deg.F. Next: The Effect Previous: The Packing Department
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