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

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

Manganese
Manganese adds considerably to the tensile strength of steel,...

Flange Shields For Furnaces
Such portable flame shields as the one illustrated in Fig. 1...

Highly Stressed Parts
The highly stressed parts on the Liberty engine consisted of ...

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

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

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

Corrosion
This steel like any other steel when distorted by cold worki...

Annealing Work
With the exception of several of the higher types of alloy s...

Using Illuminating Gas
The choice of a carburizing furnace depends greatly on the fa...

Vanadium
Vanadium has a very marked effect upon alloy steels rich in c...

The Theory Of Tempering
Steel that has been hardened is generally harder and more br...

Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrom...

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

The Care Of Carburizing Compounds
Of all the opportunities for practicing economy in the heat-t...

Annealing To Relieve Internal Stresses
Work quenched from a high temperature and not afterward tempe...

Silicon
Silicon prevents, to a large extent, defects such as gas bubb...

The Thermo-couple
With the application of the thermo-couple, the measurement of...

Pyrometry And Pyrometers
A knowledge of the fundamental principles of pyrometry, or th...



Piston Pin






Category: APPLICATION OF LIBERTY ENGINE MATERIALS TO THE AUTOMOTIVE INDUSTRY

The piston pin on an aviation engine must possess maximum resistance
to wear and to fatigue. For this reason, the piston pin is considered,
from a metallurgical standpoint, the most important part on the
engine to produce in quantities and still possess the above
characteristics. The material used for the Liberty engine piston
pin was S. A. E. No. 2315 steel, which is of the following chemical
composition: Carbon, 0.100 to 0.200 per cent; manganese, 0.500
to 0.800 per cent; phosphorus, 0.040 maximum per cent; sulphur,
0.045 maximum per cent; nickel, 3.250 to 3.750 per cent.

Each finished piston pin, after heat treatment, must show a minimum
scleroscope hardness of the case of 70, a scleroscope hardness of
the core of from 35 to 55 and a minimum crushing strength when
supported as a beam and the load applied at the center of 35,000
lb. The heat treatment used to obtain the above physical properties
consisted in carburizing at a temperature not to exceed 1,675 deg.F.,
for a sufficient length of time to secure a case of from 0.02 to
0.04 in. deep. The pins are then allowed to cool slowly from the
carbonizing heat, after which the hole is finish-machined and the
pin cut to length. The finish heat treatment of the piston pin
consisted in quenching in oil from a temperature of from 1,525 to
1,575 deg.F. to refine the grain of core properly and then quenching in
oil at a temperature of from 1,340 to 1,380 deg.F. to refine and harden
the grain of the case properly, as well as to secure proper hardness
of core. After this quenching, all piston pins are tempered in oil
at a temperature of from 375 to 400 deg.F. A 100 per cent inspection
for scleroscope hardness of the case and the core was made, and
no failures were ever recorded when the above material and heat
treatment was used.





Next: Application To The Automotive Industry

Previous: Crankshaft



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