Microstructure, Mechanical Properties and Corrosion Resistance of Modified S21603 Steel with Reduced Molybdenum Content

Abstract

This work presents a comparative study of the microstructure, mechanical properties, and corrosion resistance of conventional AISI 316L steel and a modified high-nitrogen S21603 steel containing 1% molybdenum and 0.35% nitrogen. The modified alloy exhibits significantly higher strength while maintaining acceptable ductility and impact toughness. Corrosion tests in chloride, sulfuric, and mixed acidic environments demonstrate a substantial improvement in pitting, intergranular, and general corrosion resistance due to the combined effect of nitrogen and increased chromium content. Electrochemical measurements further confirm the higher pitting potential of the modified steel. These results highlight the strong potential of high-nitrogen austenitic stainless steels as cost-effective materials for aggressive corrosion-prone applications.