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

Phosphorus
Phosphorus is one of the impurities in steel, and it has been...

Annealing In Bone
Steel and cast iron may both be annealed in granulated bone. ...

Machineability
Reheating for machine ability was done at 100 deg. less than ...

Knowing What Takes Place
How are we to know if we have given a piece of steel the ver...

Nickel-chromium
A combination of the characteristics of nickel and the charac...

Pyrometers For Molten Metal
Pyrometers for molten metal are connected to portable thermoc...

The Quenching Tank
The quenching tank is an important feature of apparatus in c...

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

Carburizing Low-carbon Sleeves
Low-carbon sleeves are carburized and pushed on malleable-ir...

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

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

Heating
Although it is possible to work steels cold, to an extent de...

Hardening High-speed Steels
We will now take up the matter of hardening high-speed steels...

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

Hardening Carbon Steel For Tools
For years the toolmaker had full sway in regard to make of st...

Double Annealing
Water annealing consists in heating the piece, allowing it to...

Care In Annealing
Not only will benefits in machining be found by careful anne...

Quenching
It is considered good practice to quench alloy steels from th...

Heat Treatment Of Gear Blanks
This section is based on a paper read before the American Gea...

The Influence Of Size
The size of the piece influences the physical properties obta...



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 2859