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Steel Making

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

The Packing Department
In Fig. 56 is shown the packing pots where the work is packe...

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

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

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

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

Correction By Zero Adjustment
Many pyrometers are supplied with a zero adjuster, by means ...

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

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

Heat Treatment Of Steel
Heat treatment consists in heating and cooling metal at defin...

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

Forging High-speed Steel
Heat very slowly and carefully to from 1,800 to 2,000 deg.F....

S A E Heat Treatments
The Society of Automotive Engineers have adopted certain heat...

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

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

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

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

Brown Automatic Signaling Pyrometer
In large heat-treating plants it has been customary to mainta...

Process Of Carburizing
Carburizing imparts a shell of high-carbon content to a low-...

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



Introduction Of Carbon






Category: CASE-HARDENING OR SURFACE-CARBURIZING

The matter to which these notes are primarily directed is the
introduction of carbon into the case of the article to be hardened.
In the first place the chances of success are increased by selecting
as few brands of steel as practicable to cover the requirements of
each component of the mechanism. The hardener is then able to become
accustomed to the characteristics of that particular material, and
after determining the most suitable treatment for it no further
experimenting beyond the usual check-test pieces is necessary.

Although a certain make of material may vary in composition from
time to time the products of a manufacturer of good steel can be
generally relied upon, and it is better to deal directly with him
than with others.

In most cases the case-hardening steels can be chosen from the
following: (1) Case-hardening mild steel of 0.20 per cent carbon;
(2) case-hardening 3-1/2 per cent nickel steel; (3) case-hardening
nickel-chromium steel; (4) case-hardening chromium vanadium. After
having chosen a suitable steel it is best to have the sample analyzed
by reliable chemists and also to have test pieces machined and pulled.

To prepare samples for analysis place a sheet of paper on the table
of a drilling machine, and with a 3/8-in. diameter drill, machine
a few holes about 3/8 in. deep in various parts of the sample bar,
collecting about 3 oz. of fine drillings free from dust. This can be
placed in a bottle and dispatched to the laboratory with instructions
to search for carbon, silicon, manganese, sulphur, phosphorus and
alloys. The results of the different tests should be carefully
tabulated, and as there would most probably be some variation an
average should be made as a fair basis of each element present,
and the following tables may be used with confidence when deciding
if the material is reliable enough to be used.

TABLE 16.--CASE-HARDENING MILD STEEL OF 0.20 PER CENT CARBON

Carbon 0.15 to 0.25 per cent
Silicon Not over 0.20 per cent
Manganese 0.30 to 0.60 per cent
Sulphur Not over 0.04 per cent
Phosphorus Not over 0.04 per cent

A tension test should register at least 60,000 lb. per square inch.

TABLE 17.--CASE-HARDENING 3-1/2 PER CENT NICKEL STEEL

Carbon 0.12 to 0.20 per cent
Manganese 0.65 per cent
Sulphur Not over 0.045 per cent
Phosphorus Not over 0.04 per cent
Nickel 3.25 to 3.75 per cent

TABLE 18.--CASE-HARDENING NICKEL CHROMIUM STEEL

Carbon 0.15 to 0.25 per cent
Manganese 0.50 to 0.80 per cent
Sulphur Not over 0.045 per cent
Phosphorus Not over 0.04 per cent
Nickel 1 to 1.5 per cent
Chromium 0.45 to 0.75 per cent

TABLE 19.--CASE-HARDENING CHROMIUM VANADIUM STEEL

Carbon Not over 0.25 per cent
Manganese 0.50 to 0.85 per cent
Sulphur Not over 0.04 per cent
Phosphorus Not over 0.04 per cent
Chromium 0.80 to 1.10 per cent
Vanadium Not less than 0.15 per cent

Having determined what is required we now proceed to inquire into
the question of carburizing, which is of vital importance.





Next: Using Illuminating Gas

Previous: The Penetration Of Carbon



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