Toward High-Pitting Resistance and Low-Cost Austenitic Stainless Steel: The Role of Carbon Alloying

This article investigates the pitting resistance of a newly developed Fe-Cr-Mn-N austenitic stainless steel with 0.14 wt% carbon and its counterpart with 0.02 wt% carbon. By using especially hot-rolled bimetal specimens, we focus on the pitting behavior near the interface between the two alloys and demonstrate that solid solution carbon can significantly improve pitting resistance. The alloyed carbon increases the passive film stability, but the more fundamental reason is that carbon suppresses the active dissolution rate of the matrix, thereby inhibiting the kinetics of pitting growth. These results will highlight the use of carbon alloying in austenitic stainless steel to provide more cost-effective materials with improved corrosion resistance and mechanical strength for the construction industry.