Informational Site NetworkInformational Site Network
Privacy
 
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

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

Tempering Round Dies
A number of circular dies of carbon tool steel for use in too...

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

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

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

Preparing Parts For Local Case-hardening
At the works of the Dayton Engineering Laboratories Company, ...

Properties Of Steel
Steels are known by certain tests. Early tests were more or l...

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...

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

The Leeds And Northrup Potentiometer System
The potentiometer pyrometer system is both flexible and subst...

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

Steel Worked In Austenitic State
As a general rule steel should be worked when it is in the a...

Carburizing Material
The simplest carburizing substance is charcoal. It is also th...

Preventing Decarbonization Of Tool Steel
It is especially important to prevent decarbonization in such...

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

Care In Annealing
Not only will benefits in machining be found by careful anne...

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

Sulphur
Sulphur is another impurity and high sulphur is even a greate...

Nickel
Nickel may be considered as the toughest among the non-rare a...



Carburizing Material






Category: CASE-HARDENING OR SURFACE-CARBURIZING

The simplest carburizing substance is charcoal. It is also the
slowest, but is often used mixed with something that will evolve
large volumes of carbon monoxide or hydrocarbon gas on being heated.
A great variety of materials is used, a few of them being charcoal
(both wood and bone), charred leather, crushed bone, horn, mixtures
of charcoal and barium carbonate, coke and heavy oils, coke treated
with alkaline carbonates, peat, charcoal mixed with common salt,
saltpeter, resin, flour, potassium bichromate, vegetable fibre,
limestone, various seed husks, etc. In general, it is well to avoid
complex mixtures.

H. L. Heathcote, on analyzing seventeen different carburizers, found
that they contained the following ingredients:

Per cent
Moisture 2.68 to 26.17
Oil 0.17 to 20.76
Carbon (organic) 6.70 to 54.19
Calcium phosphate 0.32 to 74.75
Calcium carbonate 1.20 to 11.57
Barium carbonate nil to 42.00
Zinc oxide nil to 14.50
Silica nil to 8.14
Sulphates (SO3) trace to 3.45
Sodium chloride nil to 7.88
Sodium carbonate nil to 40.00
Sulphides (S) nil to 2.80

Carburizing mixtures, though bought by weight, are used by volume,
and the weight per cubic foot is a big factor in making a selection.
A good mixture should be porous, so that the evolved gases, which
should be generated at the proper temperature, may move freely
around the steel objects being carburized; should be a good conductor
of heat; should possess minimum shrinkage when used; and should
be capable of being tamped down.

Many secret mixtures are sold, falsely claimed to be able to
convert inferior metal into crucible tool steel grade. They are
generally nothing more than mixtures of carbonaceous and cyanogen
compounds possessing the well-known carburizing properties of those
substances.





Next: Quenching

Previous: Rate Of Absorption



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 3835