Steelmaking.ca Home Steel Making Categories Manufacturing and the Economy of Machinery

Steel Making

A Satisfactory Luting Mixture
A mixture of fireclay and sand will be found very satisfactor...

Chrome-nickel Steel
Forging heat of chrome-nickel steel depends very largely on ...

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

For Milling Cutters And Formed Tools
FORGING.--Forge as before.--ANNEALING.--Place the steel in a ...

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

Piston Pin
The piston pin on an aviation engine must possess maximum res...

Rate Of Absorption
According to Guillet, the absorption of carbon is favored by ...

Separating The Work From The Compound
During the pulling of the heat, the pots are dumped upon a ca...

The Electric Process
The fourth method of manufacturing steel is by the electric f...

Pyrometers
Armor plate makers sometimes use the copper ball or Siemens' ...

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

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

Properties Of Alloy Steels
The following table shows the percentages of carbon, manganes...

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

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

Sulphur
SULPHUR is another element (symbol S) which is always found i...

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

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

Gears
The material used for all gears on the Liberty engine was sel...

Gas Consumption For Carburizing
Although the advantages offered by the gas-fired furnace for ...



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



Add to Informational Site Network
Report
Privacy
ADD TO EBOOK


Viewed 6693