X60管线钢在模拟原油沉积水中的电化学行为

为弄清各因素下,原油输送管道在原油沉积水中的腐蚀机理,通过动电位扫描法和电化学阻抗谱分别研究了X60管线钢在模拟原油沉积水中的电化学行为,研究了Cl~-、HCO_3~-、SO_4~(2-)等的浓度对X60管线钢电化学行为的影响。结果表明:在试验浓度内,Cl~-浓度为25 000 mg/L时腐蚀速率最大,极化电阻最小,随着Cl~-浓度的继续增大,自腐蚀电流有所降低;随着HCO_3~-浓度的增大,自腐蚀电流密度先增大后减小,当HCO_3~-浓度为6 000 mg/L时,自腐蚀电流密度最大;SO_4~(2-)浓度的增大促进了X60管线钢在沉积水中的腐蚀。

Electrochemical Behavior of X60 Pipeline Steel in Crude Oil Sedimentary Water

The impact of Cl-,HCO3,SO2-concentrations on the electrochemical behaviors of X60 pipeline steel in sedimentary water was studied by electrochemical impedance spectroscopy and dynamic potential scanning methods.Results showed that in the scope of test concentration,when the Cl-concentration was 25 000 mg/L,the corrosion current density was the maximum and the polarization resistance was the minimum.The corrosion current density decreased with the increase of Cl-concentration.The corrosion current density increased firstly and then decreased with the increase of HCO3-concentration.With HCO3-concentration of 6 000 mg/L,the corrosion current density reached the maximum.Besides,the increase of SO42-concentration could promote the corrosion of X60 in sedimentary water.