What are the factors influencing the rate of corrosion? Explain any two factors?
Answers
Corrosion Under Insulation: CUI is any type of corrosion that occurs in carbon and low alloy steel equipments due moisture buildup on the external surface of insulated equipment.CUI is a form of corrosion occurs when water is absorbed by or collected in the insulation. When the equipment exposed to water and oxygen it begins corrode. If CUI is undetected it leads to the shutdown of a entire facility.
Key Issue Regarding Corrosion:
More the reactivity of metal, the more will be the possibility of the metal getting corroded.
Industry use Carbon Steel as a metal type which is corrode readily when wet.
The impurities help in setting up voltaic cells, which increase the speed of corrosion
Presence of electrolytes in water also increases the rate of corrosion
Presence of in natural water increase rusting of iron.
When the iron surface is coated with layers of metals more active than iron, then the rate of corrosion is retarded.
A rise in temperature (with in a reasonable limit) increases the rate of corrosion.
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