Formation of Cr23C6 during the Sensitization of AISI 304 Stainless Steel and its Effect to Pitting Corrosion

The metallic carbide precipitation was observed after the sensitization of AISI 304 stainless steel specimens in neutral flame by using oxy-fuel and slowly cooled in the air. Correlation between corrosion and X-Ray Diffraction (XRD) shows that the enrichment of Cr23C6 in the microstructure of AISI 304 worsens the pitting corrosion resistance properties as the sensitization time increases from 5 to 60 s. However, the precipitation dissolved and corrosion resistance properties improved after the specimens treated in solution quenching treatment at 1130 oC, soaked from 24 – 120 min, then rapidly cooled in water.