"A RECIPE FOR RUST "
Take
2 parts iron (FE).
Combine
with 3 parts Oxygen (O).
Add
water and salt to taste.
Increase
temperature to speed up process.
TEMPERATURE: Generally
corrosion rates increase with increases in temperature. This is due to several interrelated
factors:
1.Higher
temperatures tend to promote the corrosion reaction kinetics. Therefore except
in cases where oxygen is free to escape, higher temperatures boost the
corrosion rate. (Essentially makes the corrosion reaction go to completion
more quickly)
2.Corrosive
by-products will have a higher diffusion rate at higher temperatures and thus
will be delivered to the corroding surface more efficiently.
(Note: In open
systems certain corrosive gases actually have lower solubility at higher
temperatures. Thus an increase in temperature may result in a decrease in the
corrosive gas solubility and accordingly a decrease in the corrosion rate as
well.)
pH: Almost
without exception the rate of corrosion increases with decreasing pH (increased
acidity).
This is due to corresponding increase in the H+
(hydrogen ion) concentration as well as the associated increase in the
solubility of most other potentially corrosion enhancing substances.
OXYGEN AND OXIDIZER LEVELS:
As one would suspect oxygen acts as an oxidizing agent in the
corrosion process as do other common oxidizers such as Cl2 (chlorine gas)
and Br2 (bromine gas). As the concentration of these agents rises, corrosion
rates increase.
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