Point test method for nitric acid. This method utilizes the inherent corrosion resistance of stainless steel pipes to concentrated and dilute nitric acid to distinguish most metals from stainless steel pipes.
The high-carbon 420 and 440 steels will be slightly corroded by nitric acid during the nitric acid test, and non-ferrous metals will be rapidly corroded by concentrated nitric acid. Dilute nitric acid is very corrosive to carbon steel.
