Sings.ca - Download the EBook Advice for SingersInformational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

Steel Worked In Austenitic State
As a general rule steel should be worked when it is in the a...

Standard Analysis
The selection of a standard analysis by the manufacturer is t...

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

Effect Of Different Carburizing Material
[Illustrations: FIGS. 33 to 37.] Each of these different p...

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

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

Leeds And Northrup Optical Pyrometer
The principles of this very popular method of measuring tempe...

Phosphorus
PHOSPHORUS is an element (symbol P) which enters the metal fr...

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

Optical System And Electrical Circuit Of The Leeds & Northrup Optical Pyrometer
For extremely high temperature, the optical pyrometer is lar...

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

Testing And Inspection Of Heat Treatment
The hard parts of the gear must be so hard that a new mill f...

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

Compensating Leads
By the use of compensating leads, formed of the same materia...

Mushet And Bessemer
That Mushet was "used" by Ebbw Vale against Bessemer is, perh...

Non-shrinking Oil-hardening Steels
Certain steels have a very low rate of expansion and contract...

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

Sulphur
Sulphur is another impurity and high sulphur is even a greate...

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

High-carbon Machinery Steel
The carbon content of this steel is above 30 points and is ha...



Rate Of Cooling






Category: APPLICATION OF LIBERTY ENGINE MATERIALS TO THE AUTOMOTIVE INDUSTRY

At the option of the manufacturer, the above treatment of gear
forgings could be substituted by normalizing the forgings at a
temperature of from 1,550 to 1,600 deg.F. The most important criterion
for proper normalizing, consisted in allowing the forgings to cool
through the critical temperature of the steel, at a rate not to exceed
50 deg.F. per hour. For the two standard steels used, this consisted in
cooling from the normalizing temperature down to a temperature
of 1,100 deg.F., at the rate indicated. Forgings normalized in this
manner will show a Brinell hardness of from 177 to 217. The question
has been repeatedly asked as to which treatment will produce the
higher quality finished part. In answer to this I will state that
on simple forgings of comparatively small section, the normalizing
treatment will produce a finished part which is of equal quality to
that of the quenched and annealed forgings. However, in the case of
complex forgings, or those of large section, more uniform physical
properties of the finished part will be obtained by quenching and
annealing the forgings in the place of normalizing.

The heat treatment of the finished gears consisted of quenching
in oil from a temperature of from 1,420 to 1,440 deg.F. for the No.
X-3,340 steel, or from a temperature of from 1,500 to 1,540 deg.F.
for No. 6,140 steel, followed by tempering in saltpeter or in an
electric furnace at a temperature of from 650 to 700 deg.F.

The question has been asked by many engineers, why is the comparatively
low scleroscope hardness specified for gears? The reason for this is
that at best the life of an aviation engine is short, as compared with
that of an automobile, truck or tractor, and that shock resistance
is of vital importance. A sclerescope hardness of from 55 to 65
will give sufficient resistance to wear to prevent replacements
during the life of an aviation engine, while at the same time this
hardness produces approximately 50 per cent greater shock-resisting
properties to the gear. In the case of the automobile, truck or
tractor, resistance to wear is the main criterion and for that
reason the higher hardness is specified.

Great care should be taken in the design of an aviation engine
gear to eliminate sharp corners at the bottom of teeth as well
as in keyways. Any change of section in any stressed part of an
aviation engine must have a radius of at least 1/32 in. to give
proper shock and fatigue resistance. This fact has been demonstrated
many times during the Liberty engine program.





Next: Connecting Rods

Previous: Gears



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 3304