Carburizing By Gas
: CASE-HARDENING OR SURFACE-CARBURIZING: The Working Of Steel
The process of carburizing by gas, briefly mentioned on page 88,
consists of having a slowly revolving, properly heated, cylindrical
retort into which illuminating gas (a mixture of various hydrocarbons)
is continuously injected under pressure. The spent gases are vented
to insure the greatest speed in carbonizing. The work is constantly
and uniformly exposed to a clean carbonizing atmosphere instead
of partially spent carbonaceous solids which may give off very
complex compounds of phosphorus, sulphur, carbon and nitrogen.
Originally this process was thought to require a gas generator but
it has been discovered that city gas works all right. The gas consists
of vapors derived from petroleum or bituminous coal. Sometimes the
gas supply is diluted by air, to reduce the speed of carburization
and increase the depth.
More
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Annealing
ANNEALING can be done by heating to temperatures ranging from 1,290 to 1,380 deg.F. and cooling in air or quenching in water or oil. After this treatment the forgings will have a hardness of about 200 Brinell and a tensile strength of 100,000 to 112... Annealing
There is no mystery or secret about the proper annealing of different steels, but in order to secure the best results it is absolutely necessary for the operator to know the kind of steel which is to be annealed. The annealing of steel is primarily ... Annealing Alloy Steel
The term alloy steel, from the steel maker's point of view, refers largely to nickel and chromium steel or a combination of both. These steels are manufactured very largely by the open-hearth process, although chromium steels are also a crucible pro... Annealing In Bone
Steel and cast iron may both be annealed in granulated bone. Pack the work the same as for case-hardening except that it is not necessary to keep the pieces away from each other. Pack with bone that has been used until it is nearly white. Heat as ho... Annealing Method
Forgings which are too hard to machine are put in pots with a little charcoal to cause a reducing atmosphere and to prevent scale. The covers are then luted on and the pots placed in the furnace. Carbon steel from 15 to 25 points is annealed at 1,6... Annealing Of High-speed Steel
For annealing high-speed steel, some makers recommend using ground mica, charcoal, lime, fine dry ashes or lake sand as a packing in the annealing boxes. Mixtures of one part charcoal, one part lime and three parts of sand are also suggested, or two... Annealing Of Rifle Components At Springfield Armory
In general, all forgings of the components of the arms manufactured at the Armory and all forgings for other ordnance establishments are packed in charcoal, lime or suitable material and annealed before being transferred from the forge shop. Exce... Annealing To Relieve Internal Stresses
Work quenched from a high temperature and not afterward tempered will, if complex in shape, contain many internal stresses which may later cause it to break. They may be eased off by slight heating without materially lessening the hardness of the pi... Annealing Work
With the exception of several of the higher types of alloy steels, where the percentages of special elements run quite high, which causes a slight air-hardening action, the carburizing steels are soft enough for machining when air cooled from any t... Application Of Liberty Engine Materials To The Automotive Industry
The success of the Liberty engine program was an engineering achievement in which the science of metallurgy played an important part. The reasons for the use of certain materials and certain treatments for each part are given with recommendation... Application To The Automotive Industry
The information given on the various parts of the Liberty engine applies with equal force to the corresponding parts in the construction of an automobile, truck or tractor. We recommend as first choice for carbon-steel screw-machine parts material p... Bessemer Process
The bessemer process consists of charging molten pig iron into a huge, brick-lined pot called the bessemer converter, and then in blowing a current of air through holes in the bottom of the vessel into the liquid metal. The air blast burns the wh... Blending The Compound
Essentially, this consists of the sturdy, power-driven separator and fanning mill which separates the foreign matter from the compound and elevates it into a large settling basin which is formed by the top of the steel housing that incloses the appa... Brown Automatic Signaling Pyrometer
In large heat-treating plants it has been customary to maintain an operator at a central pyrometer, and by colored electric lights at the furnaces, signal whether the temperatures are correct or not. It is common practice to locate three lights abov... Calibration Of Pyrometer With Common Salt
An easy and convenient method for standardization and one which does not necessitate the use of an expensive laboratory equipment is that based upon determining the melting point of common table salt (sodium chloride). While theoretically salt that ... Carbon In Tool Steel
Carbon tool steel, or tool steel as it is commonly called, usually contains from 80 to 125 points (or from 0.80 to 1.25 per cent) of carbon, and none of the alloys which go to make up the high speed steels. This was formerly known also as crucible o... Carbon Steels For Different Tools
All users of tool steels should carefully study the different qualities of the steels they handle. Different uses requires different kinds of steel for best results, and for the purpose of designating different steels some makers have adopted the tw... Carbon Tool Steel
Heat to a bright red, about 1,500 to 1,550 deg.F. Do not hammer steel when it cools down to a dark cherry red, or just below its hardening point, as this creates surface cracks. ... Carbon-steel Forgings
Low-stressed, carbon-steel forgings include such parts as carbureter control levers, etc. The important criterion for parts of this type is ease of fabrication and freedom from over-heated and burned forgings. The material used for such parts was S.... Carburizing By Gas
The process of carburizing by gas, briefly mentioned on page 88, consists of having a slowly revolving, properly heated, cylindrical retort into which illuminating gas (a mixture of various hydrocarbons) is continuously injected under pressure. The ... Carburizing Low-carbon Sleeves
Low-carbon sleeves are carburized and pushed on malleable-iron differential-case hubs. Formerly, these sleeves were given two treatments after carburization in order to refine the case and the core, and then sent to the grinding department, where t... Carburizing Material
The simplest carburizing substance is charcoal. It is also the slowest, but is often used mixed with something that will evolve large volumes of carbon monoxide or hydrocarbon gas on being heated. A great variety of materials is used, a few of them ... Care In Annealing
Not only will benefits in machining be found by careful annealing of forgings but the subsequent troubles in the hardening plant will be greatly reduced. The advantages in the hardening start with the carburizing operation, as a steel of uniform an... Case-hardening Treatments For Various Steels
Plain water, salt water and linseed oil are the three most common quenching materials for case-hardening. Water is used for ordinary work, salt water for work which must be extremely hard on the surface, and oil for work in which toughness is the ma... Chrome-nickel Steel
Forging heat of chrome-nickel steel depends very largely on the percentage of each element contained in the steel. Steel containing from 1/2 to 1 per cent chromium and from 1-1/2 to 3-1/2 per cent nickel, with a carbon content equal to the chromium... Chromium
Chromium when alloyed with steel, has the characteristic function of opposing the disintegration and reconstruction of cementite. This is demonstrated by the changes in the critical ranges of this alloy steel taking place slowly; in other words, it ... Classifications Of Steel
Among makers and sellers, carbon tool-steels are classed by grade and temper. The word grade is qualified by many adjectives of more or less cryptic meaning, but in general they aim to denote the process and care with which the steel is made. Tem... Compensating Leads
By the use of compensating leads, formed of the same material as the thermo-couple, the cold junction can be removed from the head of the thermo-couple to a point 10, 20 or 50 ft. distant from the furnace, where the temperature is reasonably consta... Complete Calibration Of Pyrometers
For the complete calibration of a thermo-couple of unknown electromotive force, the new couple may be checked against a standard instrument, placing the two bare couples side by side in a suitable tube and taking frequent readings over the range of... Composition And Properties Of Steel
It is a remarkable fact that one can look through a dozen text books on metallurgy and not find a definition of the word steel. Some of them describe the properties of many other irons and then allow you to guess that everything else is steel. If it... Composition Of Transmission-gear Steel
If the nickel content of this steel is eliminated, and the percentage of chromium raised slightly, an ideal transmission-gear material is obtained. This would, therefore, be of the following composition: Carbon, 0.470 to 0.520 per cent; manganese, 0... Conclusions
Martien was probably never a serious contender for the honor of discovering the atmospheric process of making steel. In the present state of the record, it is not an unreasonable assumption that his patent was never seriously exploited and that the ... Connecting Rods
The material used for all connecting rods on the Liberty engine was selected at the option of the manufacturer from one of two standard S. A. E. steels, the composition of which are given in Table 13. TABLE 13.--COMPOSITION OF STEELS NOS. X-3,335... Correction By Zero Adjustment
Many pyrometers are supplied with a zero adjuster, by means of which the pointer can be set to any actual cold-junction temperature. If the cold junction of the thermo-couple is in a temperature of 100 deg.F., the pointer can be set to this point o... Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrometer is dependent on the difference in temperature between its hot junction, inside the furnace, and the cold junction, or opposite end of the thermo-couple to which the copper wires are c... Corrosion
This steel like any other steel when distorted by cold working is more sensitive to corrosion and will rust. Rough cut surfaces will rust. Surfaces finished with a fine cut are less liable to rust. Ground and polished surfaces are practically immune... Crankshaft
The crankshaft was the most highly stressed part of the entire Liberty engine, and, therefore, every metallurgical precaution was taken to guarantee the quality of this part. The material used for the greater portion of the Liberty crankshafts produ... Critical Points
One of the most important means of investigating the properties of pure metals and their alloys is by an examination of their heating and cooling curves. Such curves are constructed by taking a small piece and observing and recording the temperature...