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WHAT IS CORROSION ? cor·ro·sion (k
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 | The act or process of corroding. |
| The condition produced by corroding. |
| a substance, such as rust, formed by corroding. |
Corrosion is derived from the Latin "corrosus" meaning gnawed away. Corrosion may be further defined as a gradual destruction of a material, a substance, or an entity, usually by solution or other means attributed to a chemical process.
Corrosion penetration for a steel pipe pile (20 years of marine immersion)
Active corrosion
at numerous locations were coating has failed
Simply, corrosion is an Electrochemical reaction and is defined as a chemical reaction involving the transfer of electrons. While corrosion can take any one of several forms, the mechanism of attack in an aqueous solution will involve some aspect of electrochemistry. There will be a flow of electricity from certain areas of the metal surface to other areas through a solution capable of conducting electricity, like seawater, fresh water, soils, etc.
The term anode is used to describe the portion of the metal surface that is corroded and from which current leaves the metal to enter the solution. The term cathode is used to describe the metal surface from which current leaves the solution and returns to the metal. The circuit is completed outside the solution through the direct metal contact or through a conductor joining the two pieces of metal.
Why Metals Corrode - T.R.B. Watson (167k pdf)
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Copyright © 2001 WEST COAST CORROSION PREVENTION LTD. |
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