The alloying element, nitrogen (N) is known to improve the resistance to the localized corrosion such as pitting and crevice corrosion of austenitic stainless steels. Effects of N addition on the resistances to localized corrosion of types 316L and 316LN austenitic stainless steels were investigated in the aqueous 1N NaCl solution. In order to compare the pitting corrosion resistance between stainless steels, critical pitting temperatures were measured with the change of N content, according to ASTM G-150 specification. Crevice corrosion tests were performed with the artificial crevice by using the specially designed crevice cell apparatus with both a crevice manupulator and a luggin probe. Results showed that the increase in N content caused the increase in the critical pitting temperature. N also led to improve the crevice corrosion resistance due to the decrease in the potential-drop while the increase in the solution temperature caused the expansion of the crevice region, increasing the potential-drop within the crevice. The acidification within crevice was also attributed to the crevice corrosion, in addition to the increase of the potential-drop of the inside of crevice.
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