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Furnace Data
In order to give definite information concerning furnaces, fu...

Hardness Testing
The word hardness is used to express various properties of me...

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

Annealing Alloy Steel
The term alloy steel, from the steel maker's point of view, r...

Oil-hardening Steel
Heat slowly and uniformly to 1,450 deg.F. and forge thorough...

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

Effect Of A Small Amount Of Copper In Medium-carbon Steel
This shows the result of tests by C. R. Hayward and A. B. Joh...

Open Hearth Process
The open hearth furnace consists of a big brick room with a l...

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

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

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

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

Calibration Of Pyrometer With Common Salt
An easy and convenient method for standardization and one whi...

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

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

A Chromium-cobalt Steel
The Latrobe Steel Company make a high-speed steel without tun...

Cutting-off Steel From Bar
To cut a piece from an annealed bar, cut off with a hack saw,...

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

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

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



Nickel-chromium






Category: ALLOYS AND THEIR EFFECT UPON STEEL

A combination of the characteristics of nickel and the characteristics
of chromium, as described, should obviously give a very excellent
steel as the nickel particularly affects the ferrite of the steel
and the chromium the carbon. From this combination, we are able to
get a very strong ferrite matrix and a very hard tough cementite.
The strength of a strictly pearlitic steel over a pure iron is due
to the pearlitic being a layer arrangement of cementite running
parallel to that of a pure iron layer in each individual grain. The
ferrite i.e., the iron is increased in strength by the resistance
offered by the cementite which is the simple iron-carbon combination
known to metallurgists as Fe3C. The cementite, although adding
to the tensile strength, is very brittle and the strength of the
pearlite is the combination of the ferrite and cementite. In the
event of the cementite being strengthened, as in the case of strictly
chromium steels, an increased tensile strength is readily obtained
without loss of ductility and if the ferrite is strengthened then
the tensile strength and ductility of the metal is still further
improved.

Nickel-chromium alloy represents one of the best combinations available
at the present time. The nickel intensifies the physical characteristics
of the chromium and the chromium has a similar effect on the nickel.

For case-hardening, nickel-chromium steels seem to give very excellent
results. The carbon is very rapidly taken up in this combination,
and for that reason is rather preferable to the straight nickel steel.

With the mutually intensifying action of chromium and nickel there
is a most suitable ratio for these two alloys, and it has been found
that roughly 2-1/2 parts of nickel to about 1 part of chromium
gives the best results. Therefore, we have the standard types of
3.5 per cent nickel with 1.5 per cent chromium to 1.5 per cent
nickel with 0.6 per cent chromium and the various intermediate
types. This ratio, however, does not give the whole story of
nickel-chromium combinations, and many surprising results have
been obtained with these alloys when other percentage combinations
have been employed.





Next: Vanadium

Previous: Chromium



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