Herb Gardens.ca - Download the EBook List of HerbsInformational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

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

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

Lathe And Planer Tools
FORGING.--Gently warm the steel to remove any chill, is parti...

Quenching Tool Steel
To secure proper hardness, the cooling of quenching of steel ...

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

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

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

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

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

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

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

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...

Plant For Forging Rifle Barrels
The forging of rifle barrels in large quantities and heat-tre...

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

Steel Before The 1850's
In spite of a rapid increase in the use of machines and the ...

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

Temperatures To Use
As soon as the temperature of the steel reaches 100 deg.C. (...

Heavy Forging Practice
In heavy forging practice where the metal is being worked at...

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

Heating Of Manganese Steel
Another form of heat-treating furnace is that which is used ...



Case-hardening Treatments For Various Steels






Category: CASE-HARDENING OR SURFACE-CARBURIZING

Plain water, salt water and linseed oil are the three most common
quenching materials for case-hardening. Water is used for ordinary
work, salt water for work which must be extremely hard on the surface,
and oil for work in which toughness is the main consideration. The
higher the carbon of the case, the less sudden need the quenching
action take hold of the piece; in fact, experience in case-hardening
work gives a great many combinations of quenching baths of these
three materials, depending on their temperatures. Thin work, highly
carbonized, which would fly to pieces under the slightest blow if
quenched in water or brine, is made strong and tough by properly
quenching in slightly heated oil. It is impossible to give any
rules for the temperature of this work, so much depending on the
size and design of the piece; but it is not a difficult matter to
try three or four pieces by different methods and determine what
is needed for best results.

The alloy steels are all susceptible of case-hardening treatment;
in fact, this is one of the most important heat treatments for such
steels in the automobile industry. Nickel steel carburizes more
slowly than common steel, the nickel seeming to have the effect
of slowing down the rate of penetration. There is no cloud without
its silver lining, however, and to offset this retardation, a single
treatment is often sufficient for nickel steel; for the core is not
coarsened as much as low-carbon machinery steel and thus ordinary
work may be quenched on the carburizing heat. Steel containing
from 3 to 3.5 per cent of nickel is carburized between 1,650 and
1,750 deg.F. Nickel steel containing less than 25 points of carbon,
with this same percentage of nickel, may be slightly hardened by
cooling in air instead of quenching.

Chrome-nickel steel may be case-hardened similarly to the method just
described for nickel steel, but double treatment gives better results
and is used for high-grade work. The carburizing temperature is the
same, between 1,650 and 1,750 deg.F., the second treatment consisting
of reheating to 1,400 deg. and then quenching in boiling salt water,
which gives a hard surface and at the same time prevents distortion
of the piece. The core of chrome-nickel case-hardened steel, like
that of nickel steel, is not coarsened excessively by the first
heat treatment, and therefore a single heating and quenching will
suffice.





Next: Carburizing By Gas

Previous: Refining The Grain



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 5003