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Steel Making

Preventing Cracks In Hardening
The blacksmith in the small shop, where equipment is usually ...

Pyrometers
Armor plate makers sometimes use the copper ball or Siemens' ...

Ebbw Vale And The Bessemer Process
After his British Association address in August 1856, Besseme...

Carbon Steels For Different Tools
All users of tool steels should carefully study the different...

Plant For Forging Rifle Barrels
The forging of rifle barrels in large quantities and heat-tre...

Crankshaft
The crankshaft was the most highly stressed part of the entir...

Impact Tests
Impact tests are of considerable importance as an indication ...

Detrimental Elements
Sulphur and phosphorus are two elements known to be detrimen...

Chromium
Chromium when alloyed with steel, has the characteristic func...

Heat Treatment Of Punches And Dies Shears Taps Etc
HEATING.--The degree to which tools of the above classes shou...

Classifications Of Steel
Among makers and sellers, carbon tool-steels are classed by g...

Gas Consumption For Carburizing
Although the advantages offered by the gas-fired furnace for ...

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

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

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

Cutting-off Steel From Bar
To cut a piece from an annealed bar, cut off with a hack saw,...

The Effect
The heating at 1,600 deg.F. gives the first heat treatment w...

Composition Of Transmission-gear Steel
If the nickel content of this steel is eliminated, and the pe...

Blending The Compound
Essentially, this consists of the sturdy, power-driven separa...

Effect Of A Small Amount Of Copper In Medium-carbon Steel
This shows the result of tests by C. R. Hayward and A. B. Joh...



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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