Abstract
The effect of alloying by nitrogen was investigated on the corrosion behavior of austenitic stainless steel modified with molybdenum. The influence of the nitrogen can manifest itself either through its action in passive film, or by changing the nature of the electrolyte in the vicinity of the electrode surface. Anodic polarization curves clearly indicated that investigated nitrogen-alloyed stainless steel, and the AISI 316L steel used as a comparison, are in passive state, however, the passivation current density is much lower for the nitrogen enriched stainless steel. The occurrence of NH₄⁺ ions at the interface between the passive layer and the electrolyte, causes a locally increased pH value of the electrolyte close to the electrode surface, which makes for easier passivation of the steel. The presence of NH₄⁺ ions mainly favors the repassivation of pits or stress-corrosion cracks.

Key words
austenitic stainless steel, nitrogen alloy, formation of passive film, corrosion resistance

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