Precipitation of sulfide inclusions in steel structure and their effect on local corrosion processes

Sources and regularities of the formation of nonmetal sulfide inclusions in steel structure are analyzed. The inclusions are shown to precipitate upon reaching a critical product of sulfur and manganese concentrations in the metal matrix. For Fe-Cr, Fe-17%Cr-Ni, Fe-17%Cr-Ti, and Fe-17%Cr-14%Ni-Mo alloys, the regularities of the effect the manganese-sulfide inclusions produce on their corrosion-electrochemical characteristics of passivity and pitting-resistance are studied. A significant decrease in the local corrosion resistance of low-alloyed carbon steels due to calcium-sulfide precipitation in the metal is shown.