|
|||||
|
|
|||||
 |
Heat-Treating Service
|
|
|||
|
|
|||||
|
|
|||||
|
|
|||||
|
|
Successful heat treating requires close control over all factors affecting the heating and cooling of metals. Such control is possible only when the proper equipment is available and the equipment is selected to fit the particular job. Thus, the furnace must be of the proper size and type and must be so controlled that temperatures are kept within the limits prescribed for each operation. Even the atmosphere within the furnace affects the condition of the part being heat treated. Further, the quenching equipment and the quenching medium must be selected to fit the metal and the heat- treating operation. Finally, there must be equipment for handling parts and materials, for cleaning metals, and for straightening parts.
|
||||
|
Furnace and Salt Baths There are many different types and sizes of furnaces used in heat treatment. As a general rule, furnaces are designed to operate in certain specific temperature ranges and attempted use in other ranges frequently results in work of interior quality. In addition, using a furnace beyond its rated maximum temperature shortens its life and may necessitate costly and time consuming repairs. Fuel-fired furnaces (gas or oil) require air for proper combustion and an air compressor or blower is therefore necessary. These furnaces are usually of the muffler type: that is, the combustion of the fuel takes place outside of and around the chamber in which the work is placed. If an open muffler is used , the furnace should be designed so as to prevent the direct impingement of flame on the work. In furnaces heated by electricity the heating elements are generally in the form of wire or robbon. Good design requires incorporation of additional heating elements at locations where maximum heat loss may be expected. Such furnaces commonly operate up to a maximum temperature of about : 2000*f. Furnaces operating at temperatures up to about :2500*f, usually employ resistor bars of sintered carbides.
|
|||||
|
|||||
|
|
|||||
|
Remember our web site / Copyright@2007 / rev2 |
|||||