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Steel Making

Temperatures To Use
As soon as the temperature of the steel reaches 100 deg.C. (...

Cyanide Bath For Tool Steels
All high-carbon tool steels are heated in a cyanide bath. Wi...

Pyrometers
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Composition Of Transmission-gear Steel
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Molybdenum
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Quenching Tool Steel
To secure proper hardness, the cooling of quenching of steel ...

A Chromium-cobalt Steel
The Latrobe Steel Company make a high-speed steel without tun...

Calibration Of Pyrometer With Common Salt
An easy and convenient method for standardization and one whi...

Suggestions For Handling High-speed Steels
The following suggestions for handling high-speed steels are ...

Case-hardening Treatments For Various Steels
Plain water, salt water and linseed oil are the three most co...

Tensile Properties
Strength of a metal is usually expressed in the number of pou...

Annealing Of Rifle Components At Springfield Armory
In general, all forgings of the components of the arms manufa...

Carbon Tool Steel
Heat to a bright red, about 1,500 to 1,550 deg.F. Do not ham...

The Care Of Carburizing Compounds
Of all the opportunities for practicing economy in the heat-t...

Preventing Decarbonization Of Tool Steel
It is especially important to prevent decarbonization in such...

High Speed Steel
For centuries the secret art of making tool steel was handed ...

Robert Mushet
Robert (Forester) Mushet (1811-1891), born in the Forest of D...

Application To The Automotive Industry
The information given on the various parts of the Liberty eng...

William Kelly's Air-boiling Process
An account of Bessemer's address to the British Association w...

Tool Or Crucible Steel
Crucible steel can be annealed either in muffled furnace or b...



Plant For Forging Rifle Barrels






Category: THE FORGING OF STEEL

The forging of rifle barrels in large quantities and heat-treating
them to meet the specifications demanded by some of the foreign
governments led Wheelock, Lovejoy & Company to establish a complete
plant for this purpose in connection with their warehouse in Cambridge,
Mass. This plant, designed and constructed by their chief engineer,
K. A. Juthe, had many interesting features. Many features of this
plant can be modified for other classes of work.




The stock, which came in bars of mill length, was cut off so as to
make a barrel with the proper allowances for trimming (Fig. 21).
They then pass to the forging or upsetting press in the adjoining
room. This press, which is shown in more detail in Fig. 22, handled
the barrels from all the heating furnaces shown. The men changed
work at frequent intervals, to avoid excessive fatigue.



Then the barrels were reheated in the continuous furnace, shown
in Fig. 23, and straightened before being tested.

The barrels were next tested for straightness. After the heat-treating,
the ends are ground, a spot ground on the enlarged end and each
barrel tested on a Brinell machine. The pressure used is 3,000 kg.,
or 6,614 lb., on a 10-millimeter ball, which is standard. Hardness
of 240 was desired.

The heat-treating of the rifle blanks covered four separate operations:
(1) Heating and soaking the steel above the critical temperature
and quenching in oil to harden the steel through to the center;
(2) reheating for drawing of temper for the purpose of meeting the
physical specifications; (3) reheating to meet the machine ability
test for production purposes; and (4) reheating to straighten the
blanks while hot.

A short explanation of the necessity for the many heats may be
interesting. For the first heat, the blanks were slowly brought
to the required heat, which is about 150 deg.F. above the critical
temperature. They are then soaked at a high heat for about 1 hr.
before quenching. The purpose of this treatment is to eliminate
any rolling or heat stresses that might be in the bars from mill
operations; also to insure a thorough even heat through a cross-section
of the steel. This heat also causes blanks with seams or slight
flaws to open up in quenching, making detection of defective blanks
very easy.

The quenching oil was kept at a constant temperature of 100 deg.F.,
to avoid subjecting the steel to shocks, thereby causing surface
cracks. The drawing of temper was the most critical operation and
was kept within a 10 deg. fluctuation. The degree of heat necessary
depends entirely on the analysis of the steel, there being a certain
variation in the different heats of steel as received from the mill.





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Previous: Chrome-nickel Steel



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