Corrosion resistant degradation of AISI 304 austenitic stainless steel exposed to simulated carburizing environments

This paper aimed to evaluate the anti-corrosion performance of AISI 304 austenitic stainless steel after exposure to the simulated carburizing environment set up at 600oC, 750oC, and 900oC for 4 hrs. The microstructural alternation was investigated by Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). Electrochemical Potentiokinetic Reactivation (EPR) was employed to study the anti-corrosion performance of AISI 304 austenitic stainless steel after exposure to the simulated carburizing environment. Hardness measurement was also conducted to study the role of carbon atoms released from the simulated environment. The results showed the formation of precipitated chromium carbides along grain boundaries and sensitization degree was found in ascending order: 600oC (Pa =0.23), 750oC (Pa =0.32) and finally 900oC (Pa =0.41). All carburized conditions promote carbon dissociation and diffusion through the substrate of AISI 304 austenitic stainless steel, resulting in the increased hardness and decreased corrosion resistance of AISI 304 austenitic stainless steel after exposure to the simulated carburizing environment.