say, a corroded metal has a mass of 30g, after cleaning what's left is 25g of the remaining metal, thus is 5g of corrosion of any value? Thank you in advance.
Dear Muhammad
I would say the weight loss method of measuring the corrosion rate.
Refer to the Link:(https://www.researchgate.net/post/Tell_about_weight_loss_method_in_corrosion)
You will find answers to your question.
dear Muhammad Noh Hamzah ;
Corrosion behavior of the corroded samples can be evaluated using the weight loss method. The samples should be prepared according to the standard of surface finishing and cleaning of weight-loss samples,
the corrosion rate can be calculated according to the following equation:
(CR) mpy = 534 ×W/(D×A×T)
Where:
W = Weight loss in milligrams
D = Density of coupon in grams divided by cubic centimeters (g/cm3 )
A = Area in square inches (in2)
T = Time exposed in hours
for further details I recommend; Practice NACE RP-0775 -2005, Item No. 21017 and ASTM G-1 & G-4
Thank you everyone for the response,
However would the corrosion rate formula work for a metal that has already corroded? Meaning the initial uncorroded metal mass is unknown. Because I am only going to quantify the corrosion of only part of the metal.
dear Muhammad Noh Hamzah ; to calculate corrosion rate you should know the exposed area of metal to the corrosion environment.
Dear Dr. Muhammad Noh Hamzah,
surely the value of weight loss of a material (as gravimetric difference between a sample before and after esposition), normalized to its surface (and possibly also to the density) can be an indicator of the corrosive phenomenon. However, the assessment of degradation can not ignore the morphology of the attack. Localized corrosion phenomena can originate, in addition to negative aesthetic factors, complications related to the integrity of the material generating more important problems of structural integrity and safety.
Best regards, Pierluigi Traverso
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