Study on H2S/CO2 Electrochemical Corrosion Behavior of 80S Steel and N80 Steel in Oilfield Produced Water
The electrochemical corrosion behaviors of 80S steel and N80 steel in oilfield produced watercontaining H2S/CO2 were stud-ied by corrosion weight loss and electrochemical measurement techniques.The results show that temperature is a major factor affecting the corrosion rate in the simulated CO2/H2S corrosion environment.The corrosion rate of 80S steel and N80 steel increases with the in-crease of temperature.Uniform corrosion occurs on the surface of both materials,but the corrosion degree on the surface of N80 steel is more serious,mainly because Cr can significantly improve the protection of the corrosion product film on the metal.With the increase of temperature,the corrosion potential of both materials changes to negative direction and the corrosion currentdensityincreases.Compared with N80 steel,the corrosion current density of 80S steel is lower under different conditions,and it has better corrosion resistance.The two materials have capacitive reactance arcs in the middle to high frequency region and inductive reactance arcs in the low frequency re-gion at 25℃,and have capacitive reactance arcs in the middle to high frequency region and Warburg impedance in the low frequency region at 50℃ and 75℃.Warburg impedance shows more obvious diffusion characteristics with the increase of temperature.With the increase of temperature,Rt of two materials decreases continuously,and Zw of Warburg impedance also decreases.The higher the tem-perature,the better the protective performance of the corrosion product film generated on the metal surface,and the compactness of the corrosion product film generated on the surface of 80S steel is better than that on the surface of N80 steel.
万方数据
