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Steel Making

Judging The Heat Of Steel
While the use of a pyrometer is of course the only way to hav...

Heating Of Manganese Steel
Another form of heat-treating furnace is that which is used ...

Lathe And Planer Tools
FORGING.--Gently warm the steel to remove any chill, is parti...

Preparing Parts For Local Case-hardening
At the works of the Dayton Engineering Laboratories Company, ...

Properties Of Steel
Steels are known by certain tests. Early tests were more or l...

Air-hardening Steels
These steels are recommended for boring, turning and planing...

Heat-treating Equipment And Methods For Mass Production
The heat-treating department of the Brown-Lipe-Chapin Company...

The Thermo-couple
With the application of the thermo-couple, the measurement of...

Manganese
Manganese adds considerably to the tensile strength of steel,...

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

Placing Of Pyrometers
When installing a pyrometer, care should be taken that it re...

Hardening Operation
Hardening a gear is accomplished as follows: The gear is tak...

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

Annealing Method
Forgings which are too hard to machine are put in pots with ...

Flange Shields For Furnaces
Such portable flame shields as the one illustrated in Fig. 1...

Connecting Rods
The material used for all connecting rods on the Liberty engi...

High-chromium Or Rust-proof Steel
High-chromium, or what is called stainless steel containing f...

Nickel
Nickel may be considered as the toughest among the non-rare a...

Heat Treatment Of Lathe Planer And Similar Tools
FIRE.--For these tools a good fire is one made of hard foundr...

Steel Can Be Worked Cold
As noted above, steel can be worked cold, as in the case of ...



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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