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   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

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...

Air-hardening Steels
These steels are recommended for boring, turning and planing...

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

Refining The Grain
This is remedied by reheating the piece to a temperature slig...

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

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

Heat-treating Department
The heat-treating department occupies an L-shaped building. ...

Annealing
ANNEALING can be done by heating to temperatures ranging from...

Hints For Tool Steel Users
Do not hesitate to ask for information from the maker as to t...

Temperature For Annealing
Theoretically, annealing should be accomplished at a tempera...

Composition Of Transmission-gear Steel
If the nickel content of this steel is eliminated, and the pe...

The Effect Of Tempering On Water-quenched Gages
The following information has been supplied by Automatic and ...

Knowing What Takes Place
How are we to know if we have given a piece of steel the ver...

Making Steel Balls
Steel balls are made from rods or coils according to size, st...

Hardening
Steel is hardened by quenching from above the upper critical....

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

Annealing
There is no mystery or secret about the proper annealing of d...

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

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



Silicon






Category: COMPOSITION AND PROPERTIES OF STEEL

SILICON is a very widespread element (symbol Si), being an essential
constituent of nearly all the rocks of the earth. It is similar to
carbon in many of its chemical properties; for instance it burns
very readily in oxygen, and consequently native silicon is unknown--it
is always found in combination with one or more other elements.
When it bums, each atom of silicon unites with two atoms of oxygen
to form a compound known to chemists as silica (SiO2), and to the
small boy as sand and agate.

Iron ore (an oxide of iron) contains more or less sand and dirt
mixed in it when it is mined, and not only the iron oxide but also
some of the silicon oxide is robbed of its oxygen by the smelting
process. Pig iron--the product of the blast furnace--therefore
contains from 1 to 3 per cent of silicon, and some silicon remains
in the metal after it has been purified and converted into steel.

However, silicon, as noted above, burns very readily in oxygen,
and this property is of good use in steel making. At the end of
the steel-making process the metal contains more or less oxygen,
which must be removed. This is sometimes done (especially in the
so-called acid process) by adding a small amount of silicon to
the hot metal just before it leaves the furnace, and stirring it
in. It thereupon abstracts oxygen from the metal wherever it finds
it, changing to silica (SiO2) which rises and floats on the surface
of the cleaned metal. Most of the silicon remaining in the metal
is an excess over that which is required to remove the dangerous
oxygen, and the final analysis of many steels show enough silicon
(from 0.20 to 0.40) to make sure that this step in the manufacture
has been properly done.





Next: Manganese

Previous: Phosphorus



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