Carburizing imparts a shell of high-carbon content to a low-carbon steel. This produces what might be termed a dual steel, allowing for an outer shell which when hardened would wit...
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...
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 ai...
Steel is hardened by quenching from above the upper critical. Apparently the quick cooling prevents the normal change back to definite and sizeable crystals of ferrite and cementit...
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 i...
Heat very slowly and carefully to from 1,800 to 2,000 deg.F. and forge thoroughly and uniformly. If the forging operation is prolonged do not continue forging the tool when the ste...
Steels are known by certain tests. Early tests were more or less crude, and depended upon the ability of the workman to judge the grain exhibited by a freshly broken piece of steel...
The forgings can be hardened by cooling in still air or quenching in oil or water from a temperature between 1,650 and 1,750 deg.F. The physical properties do not vary greatly when...
FORGING.--Gently warm the steel to remove any chill, is particularly desirable in the winter, then heat slowly and carefully to a scaling heat, that is a lemon heat (1,800 to 2,000...
TO FORGE.--Gently warm the steel to remove any chill is particularly desirable in the winter. Then heat slowly and carefully to a scaling heat, that is a lemon heat (1,800 deg.-2,0...
A mixture of fireclay and sand will be found very satisfactory for closing up the boxes, and by observing the appearance of the work when taken out we can gage the suitability of t...
This shows the result of tests by C. R. Hayward and A. B. Johnston on two types of steel: one containing 0.30 per cent carbon, 0.012 per cent phosphorus, and 0.860 per cent copper,...
The piston pin on an aviation engine must possess maximum resistance to wear and to fatigue. For this reason, the piston pin is considered, from a metallurgical standpoint, the mos...
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 o...
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 h...
Sulphur and phosphorus are two elements known to be detrimental to all steels. Sulphur causes red-shortness and phosphorus causes cold-shortness. The detrimental effects of these t...
Robert (Forester) Mushet (1811-1891), born in the Forest of Dean, Gloucestershire, of a Scots father (David, 1772-1847) himself a noted contributor to the metallurgy of iron and st...
[Illustrations: FIGS. 33 to 37.] Each of these different packing materials has a different effect upon the work in which it is heated. Charcoal by itself will give a rather light c...
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 a...
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 critica...
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 t...
The Latrobe Steel Company make a high-speed steel without tungsten, its red-hardness properties depending on chromium and cobalt instead of tungsten. It is known as P. R. K-33 stee...
Commercial steels of even the simplest types are therefore primarily alloys of iron and carbon. Impurities and their remedies are always present: sulphur, phosphorus, silicon and m...
Nickel may be considered as the toughest among the non-rare alloys now used in steel manufacture. Originally nickel was added to give increased strength and toughness over that obt...
When installing a pyrometer, care should be taken that it reaches directly to the point desired to be measured, that the cold junction is kept cold, and that the wires leading to t...
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 ove...
These steels are recommended for boring, turning and planing where the cost of high-speed seems excessive. They are also recommended for hard wood knives, for roughing and finishin...
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 hard...
A combination of the characteristics of nickel and the characteristics of chromium, as described, should obviously give a very excellent steel as the nickel particularly affects th...
It has been known for fifty years that a beam or rod would fail at a relatively low stress if only repeated often enough. It has been found, however, that each material possesses a...