Abstract
This work is concerned with the effect of interstitially absorbed nitrogen on pitting corrosion if erosion corrosion is also present at the same time. The results of the investigations have shown that nitrogen, in the form of negatively charged N^3- ions, which make possible the formation of NH⁺⁴ ions, slows down the initiation and growth of pits due to the rise in the pH value in the pit, from initial acidic value to basic value. This process is also possible in the presence of Cl^- ions. As a consequence the activation energy, which is needed for the initiation of pits, is high. Under the conditions of erosion corrosion the repassivation potential is equal to the pitting potential, and in certain conditions is higher than the latter. In the case of stainless steels and alloys, which do not contain added nitrogen, this effect is not noticeable.

Key words
nitrogen-alloyed stainless steel, pitting resistance, erosion corrosion

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