Corrosion Behavior of Nitrogen-Containing Stainless Steel in Nitric Acid and Chloride Environments

The corrosion resistance of Type 304LN (UNS S30453) stainless steel containing nitrogen compositions of 0.132 wt%, 0.193 wt%, and 0.406 wt% in nitric acid (HNO₃) and chloride medium is investigated in the paper. Increasing the nitrogen content in the steel showed no deleterious effect on corrosion resistance in HNO₃. The role of nitrogen in enhancing the pitting corrosion resistance was observed on increasing the nitrogen content from 0.132 wt% to 0.193 wt%. Further increase in nitrogen content to 0.406 wt% was found detrimental, owing to the formation of chromium nitride and manganese-rich precipitates along the grain boundaries. The results are presented in the paper.