What is corrosion?
 

[CENTER][SIZE="5"][B][U]Corrosion[/U][/B][/SIZE][/CENTER]

[B][SIZE="3"][U]What is corrosion?[/U][/SIZE][/B]

[B]Definition:[/B]
"Chemically corrosion is a reaction where oxygen bonds to metal atoms forming an oxide coat."

[B][SIZE="3"][U]Good forms of corrosion?[/U][/SIZE][/B]
Although the most commonly know forms of corrosion, such as rust, are bad, one form of corrosion is very useful. It is the thin oxide layer that forms as a result of corrosion and prevents bad types of corrosion that changes the shape of the metal.

[B][SIZE="3"][U]What speeds up corrosion?[/U][/SIZE][/B]
There are many factors that can cause corrosion.

1- The type of metal plays a big role in the rate at which corrosion occurs.
[B]For example [/B]chromium corrodes much slower than iron; valuable metals like sterling silver, platinum and gold hardly corrode at all.

2-The environment also plays a role in corrosion. Metals corrode faster in hot humid climates and slower in cold dry ones. Other chemicals, such as chloride, which is commonly found in seawater and on roads in winter, can drastically increase the rates at which things corrode.


[B][SIZE="3"][U]Reactions during Spreading[/U][/SIZE][/B]
[IMG]http://www.nsls.bnl.gov/about/everyday/images/corrosion/reactions.jpg[/IMG]

[B][SIZE="3"][U]Can we stop corrosion?[/U][/SIZE][/B]

1-Although we can't stop corrosion all together, there are ways we can slow it down. Stainless steel is a mixture of chromium and steel. The outer layer forms a chromium oxide because it corrodes much slower than the iron.

2-Also if we can keep oxygen away from the metal we can slow corrosion.

3-Although we can't keep everything in a vacuum we can add a coat of paint or plastic to the metal, protecting it from the atmosphere.


[B][U][SIZE="3"][U]Fast Facts[/U][/SIZE][/U][/B]

-One of the most commonly known forms of corrosion is rust
-Rust is a layer of iron oxide on the surface of the metal
-When corrosion forms very thin layers of oxides, it helps metals keep there shape
-Corrosion costs the USA and Europe in excess of 3% of GNP (Gross National Product).
-A common way to slow corrosion is to add a layer of paint to block contact with the atmosphere.