While working on a sermon the pastor heard a knock at his office door. "Come in," he invited. A sad-looking man in threadbare clothes came in, pulling a large pig on a rope. "Can I talk to you for a minute?" asked the ma... Read more of Ten Excuses A Woman Gives For Calling Off The Relationship at Free Jokes.caInformational Site Network Informational
Privacy
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

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

Chromium
Chromium when alloyed with steel, has the characteristic func...

The Modern Hardening Room
A hardening room of today means a very different place from ...

Carbon Tool Steel
Heat to a bright red, about 1,500 to 1,550 deg.F. Do not ham...

Case-hardening Treatments For Various Steels
Plain water, salt water and linseed oil are the three most co...

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

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

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

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

Annealing Method
Forgings which are too hard to machine are put in pots with ...

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

High-chromium Or Rust-proof Steel
High-chromium, or what is called stainless steel containing f...

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

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

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

The Pyrometer And Its Use
In the heat treatment of steel, it has become absolutely nece...

Protective Screens For Furnaces
Workmen needlessly exposed to the flames, heat and glare from...

Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrom...

The Thermo-couple
With the application of the thermo-couple, the measurement of...

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



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 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 4763