LITTLE CLARENCE--"Pa!" HIS FATHER--"Well, my son?" LITTLE CLARENCE--"I took a walk through the cemetery to-day and read the inscriptions on the tombstones." HIS FATHER--"And what were your thoughts after you had done so?" LITTLE CLA... Read more of EPITAPHS at Free Jokes.caInformational Site Network Informational
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Steel Making

Bessemer Process
The bessemer process consists of charging molten pig iron int...

The Penetration Of Carbon
Carburized mild steel is used to a great extent in the manufa...

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

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

Drop Forging Dies
The kind of steel used in the die of course influences the he...

Case-hardening Treatments For Various Steels
Plain water, salt water and linseed oil are the three most co...

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

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

Surface Carburizing
Carburizing, commonly called case-hardening, is the art of pr...

For Milling Cutters And Formed Tools
FORGING.--Forge as before.--ANNEALING.--Place the steel in a ...

Sulphur
SULPHUR is another element (symbol S) which is always found i...

Affinity Of Nickel Steel For Carbon
The carbon- and nickel-steel gears are carburized separately...

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

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

Hardening High-speed Steel
In forging use coke for fuel in the forge. Heat steel slowly ...

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

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

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

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

Rate Of Cooling
At the option of the manufacturer, the above treatment of gea...



Liberty Motor Connecting Rods






Category: ALLOYS AND THEIR EFFECT UPON STEEL

The requirements for materials for the Liberty motor connecting rods
are so severe that the methods of securing the desired qualities
will be of value in other lines. The original specifications called
for chrome-nickel but the losses due to the difficulty of handling
caused the Lincoln Motor Company to suggest the substitution of
chrome-vanadium steel, and this was accepted by the Signal Corps. The
rods were accordingly made from chromium-vanadium steel, containing
carbon, 0.30 to 0.40 per cent; manganese, 0.50 to 0.80 per cent;
phosphorus, not over 0.04 per cent; sulphur, not over 0.04 per
cent; chromium, 0.80 to 1.10 per cent; vanadium, not less than 0.15
per cent. This steel is ordinarily known in the trade as 0.35 carbon
steel, S. A. E., specification 6,135, which provides a first-rate
quality steel for structural parts that are to be heat-treated.
The fatigue resisting or endurance qualities of this material are
excellent. It has a tensile strength of 150,000 lb. minimum per
square inch; elastic limit, 115,000 lb. minimum per square inch;
elongation, 5 per cent minimum in 2 in.; and minimum reduction
in area, 25 per cent.

The original production system as outlined for the manufacturers
had called for a heat treatment in the rough-forged state for the
connecting rods, and then semi-machining the rod forgings before
giving them the final treatment. The Lincoln Motor Company insisted
from the first that the proper method would be a complete heat
treatment of the forging in the rough state, and machining the
rod after the heat treatment. After a number of trial lots, the
Signal Corps acceded to the request and production was immediately
increased and quality benefited by the change. This method was
later included in a revised specification issued to all producers.

The original system was one that required a great deal of labor
per unit output. The Lincoln organization developed a method of
handling connecting rods whereby five workmen accomplished the
same result that would have required about 30 or 32 by the original
method. Even after revising the specification so as to allow complete
heat treatments in the rough-forged state, the ordinary methods
employed in heat-treating would have required 12 to 15 men. With
the fixtures employed, five men could handle 1,300 connecting rods,
half of which are plain and half, forked, in a working period of
little over 7 hr.




The increase in production was gained by devising fixtures which
enabled fewer men to handle a greater quantity of parts with less
effort and in less time.

In heat-treating the forgings were laid on a rack or loop A,
Fig. 14, made of 1-1/4-in. double extra-heavy pipe, bent up with
parallel sides about 9 in. apart, one end being bent straight across
and the other end being bent upward so as to afford an easy grasp
for the hook. Fifteen rods were laid on each loop, there being
four loops of rods charged into a furnace with a hearth area of 36
by 66 in. The rods were charged at a temperature of approximately
900 deg.F. They were heated for refining over a period of 3 hr. to
1,625 deg.F., soaked 15 min, at this degree of heat and quenched in
soluble quenching oil.

In pulling the heat to quench the rods, the furnace door was raised
and the operator pulls one of the loops A, Fig. 15 forward to
the shelf of the furnace, supporting the straight end of the loop
by means of the porter bar B. They swung the loop of rods around
from the furnace shelf and set the straight end of the loop on
the edge of the quenching tank, then raise the curved end C,
by means of their hook D so that all the rods on the loop slide
into the oil bath.

Before the rods cooled entirely, the baskets in the quenching tank
were raised and the oil allowed to partly drain off the forgings,
and they were stacked on curved-end loops or racks and charged into
the furnace for the second or hardening heat. The temperature of
the furnace was raised in 1-1/2 hr. to 1,550 deg.F., the rods soaked
for 15 min. at this degree of heat and quenched in the same manner
as above.

They were again drained while yet warm, placed on loops and charged
into the furnace for the third or tempering heat. The temperature of
the furnace was brought to 1,100 deg.F. in 1 hr., and the rods soaked at
this degree of heat for 1 hr. They were then removed from the furnace
the same as for quenching, but were dumped onto steel platforms
instead of into the quenching oil, and allowed to cool on these
steel platforms down to the room temperature.





Next: Pickling The Forgings

Previous: Corrosion



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