Corrosion rate converter
Convert corrosion rate between mils per year and millimeters per year, and see how long a wall would last.
That's 2.5× as fast as excellent resistance, while good resistance is 1.97× faster. A 10 mm wall would last about 39.37 years at that rate.
What it means
How fast is it going?
These are uniform corrosion rates. Pitting attacks one spot far faster than the average, so a good overall rate can still perforate a pipe.
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Learn
Three things worth knowing
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1 mpy = 0.0254 mm/yr
So 40 mpy is almost exactly 1 mm a year. That single anchor converts most field data in your head.
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Weight loss, converted
The measurement is really a coupon weighed before and after. Dividing the lost mass by the density and the area turns it into a thickness per year.
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Average hides the pit
A vessel losing 0.05 mm/yr on average can still spring a leak in a year if the attack concentrates in one pit. Uniform rates only describe uniform attack.
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Background
About corrosion rate
Corrosion is reported as metal thickness lost per year: mm/yr in most of the world, mils per year in the US, where a mil is a thousandth of an inch.
Under the usual ratings, below 0.025 mm/yr is outstanding and above 1.3 mm/yr is unacceptable for most plant.