Pitting Corrosion Resistance of Chromium-Nitrogen Steels with an Overequilibrium Nitrogen Content

摘要

The effect of alloying elements, such as chromium and nitrogen (at their overequilibrium contents), and heat-treatment conditions (quenching from 1200°C, tempering at 400 and 600°C for 2 h) on the pitting corrosion resistance of chromium-nitrogen steels containing 15-21% Cr and 0.4-1.22% N in chloride solutions is studied. A relation is established between the structural and phase states of the chromium-nitrogen steels and the character of anode polarization curves and the potentials of pitting formation and repassivation. It is found that the pitting corrosion resistance of the chromium-nitrogen steels tempered at a temperature of 600°C decreases significantly because of the formation of chromium nitrides.