CO2 corrosion behavior of sensitized 304 and 316 austenitic stainless steels in 3.5 wt.% NaCl solution and presence of H2S

Abstract

The CO2 corrosion behavior of sensitized and non-sensitized 304 and 316 stainless steels in the absence and presence of H2S was investigated using cyclic polarization and electrochemical impedance spectroscopy techniques. The sensitization resulted in significant negative shift on pitting potential for both alloys. The general CO2 corrosion rate of sensitized and non-sensitized samples was not significant. However, increasing H2S concentration up to 200 ppm resulted in severe increase in general corrosion rate and also significant negative shift for pitting potential. It was concluded that, the major role of sensitization is influencing the pitting potential and pitting corrosion of both alloys.