VIEW THE MOBILE VERSION of www.steelmaking.ca Informational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

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

Piston Pin
The piston pin on an aviation engine must possess maximum res...

Quenching The Work
In some operations case-hardened work is quenched from the bo...

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

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

Take Time For Hardening
Uneven heating and poor quenching has caused loss of many ve...

Liberty Motor Connecting Rods
The requirements for materials for the Liberty motor connecti...

Preventing Carburizing By Copper-plating
Copper-plating has been found effective and must have a thick...

Hardness Testing
The word hardness is used to express various properties of me...

Making Steel Balls
Steel balls are made from rods or coils according to size, st...

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

Introduction Of Carbon
The matter to which these notes are primarily directed is the...

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

Separating The Work From The Compound
During the pulling of the heat, the pots are dumped upon a ca...

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

Protective Screens For Furnaces
Workmen needlessly exposed to the flames, heat and glare from...

The Electric Process
The fourth method of manufacturing steel is by the electric f...

Composition And Properties Of Steel
It is a remarkable fact that one can look through a dozen tex...

Instructions For Working High-speed Steel
Owing to the wide variations in the composition of high-speed...

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



Machineability






Category: ANNEALING

Reheating for machine ability was done at 100 deg. less than the drawing
temperature, but the time of soaking is more than double. After
both drawing and reheating, the blanks were buried in lime where
they remain, out of contact with the air, until their temperature
had dropped to that of the workroom.

For straightening, the barrels were heated to from 900 to 1,000 deg.F.
in an automatic furnace 25 ft. long, this operation taking about 2
hr. The purpose of hot straightening was to prevent any stresses
being put into the blanks, so that after rough-turning, drilling
or rifling operations they would not have a tendency to spring
back to shape as left by the quenching bath.

A method that produces an even better machining rifle blank, which
practically stays straight through the different machining operations,
was to rough-turn the blanks, then subject them to a heat of practically
1,0000 for 4 hr. Production throughout the different operations is
materially increased, with practically no straightening required
after drilling, reaming, finish-turning or rifling operations.



FIGS. 24 and 25.--Roof system of cooling quenching oil.]

This method was tested out by one of the largest manufacturers and
proved to be the best way to eliminate a very expensive finished
gun-barrel straightening process.



The heat-treating required a large amount of cooling oil, and the
problem of keeping this at the proper temperature required considerable
study. The result was the cooling plant on the roof, as shown in
Figs. 24, 25 and 26. The first two illustrations show the plant as
it appeared complete. Figure 26 shows how the oil was handled in
what is sometimes called the ebulator system. The oil was pumped
up from the cooling tanks through the pipe A to the tank B.
From here it ran down onto the breakers or separators C, which
break the oil up into fine particles that are caught by the fans
D. The spray is blown up into the cooling tower E, which contains
banks of cooling pipes, as can be seen, as well as baffies F. The
spray collects on the cool pipes and forms drops, which fall on
the curved plates G and run back to the oil-storage tank below
ground.

The water for this cooling was pumped from 10 artesian wells at the
rate of 60 gal. per minute and cooled 90 gal. of oil per minute,
lowering the temperature from 130 or 140 to 100 deg.F. The water as
it came from the wells averaged around 52 deg.F. The motor was of a
7-1/2-hp. variable-speed type with a range of from 700 to 1,200
r.p.m., which could be varied to suit the amount of oil to be cooled.
The plant handled 300 gal. of oil per minute.





Next: Annealing

Previous: Plant For Forging Rifle Barrels



Add to del.icio.us Add to Reddit Add to Digg Add to Del.icio.us Add to Google Add to Twitter Add to Stumble Upon
Add to Informational Site Network
Report
Privacy
SHAREADD TO EBOOK


Viewed 3446