[en] The results are presented of corrosion tests and structural investigations made on type 03Cr18Ni10 and 03Cr18Ni10Mo3 steels not containing and also containing nitrogen in a quantity of 0.15-0.3%. The corrosion and electrochemical behavior of Cr20Ni20 steel with an ultralow carbon content (0.004-0.006%) and a nitrogen content within limits of 0-0.5% and also the behavior of Cr₂N nitride were investigated. A conclusion was drawn as to the influence of nitrogen and excess nitride phase on the corrosion resistance of steels in aggressive media with different oxidation and reduction properties