Corrosion of 16Mn in High Pressure Carbon Dioxide Saturated NACE Solutions with Hydrogen Sulfide

The paper deals mainly with the corrosion of 16Mn steel under the condition of three different high temperatures and in NACE solution saturated with H2S at 1MPa partial pressure of CO2, by means of autoclave, SEM, XRD, weight loss method and electron-probe micro-analysis. The result showed: under the experimental conditions, the serious CO2/H2S corrosion happened to 16Mn steel ,so that the main corrosion films, ferrous sulfide, could be clearly found on both sides of the samples; at 60°C, characteristics of pitting corrosion manifested centered chiefly around CO2 corrosion ; at 90°Cand 120°C, around H2S ones . It was the cooperating effects of both the hydrogen damage and pitting corrosion caused by CO2/H2S corrosion that formed the special corrosion features on the surface of steel to a certain degree. It was indicated that the corrosion of CO2/H2S was the result of interaction of multi-factors.