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采用动电位极化、电化学阻抗谱和Mott-Schottky等电化学测量方法研究了静水压力对X100管线钢在0.5 mol/L Na HCO3+0.03 mol/L Na Cl溶液中的电化学腐蚀行为的影响。结果表明:随静水压力增加,X100钢表面点蚀坑数量和面积增加;静水压力增加使溶液离子的活性增加,促进Cl-在钝化膜中的吸附,腐蚀反应的速率加快,腐蚀电流密度增加。静水压力增加使钝化膜组成由低压时的氧化物或氢氧化物转变为高压时的碳酸盐,导致耐蚀性降低,而点蚀形核几率增加。X100管线钢钝化膜具有n型半导体性质,随静水压力的增加,钝化膜内Cl-的增多使晶格缺陷增多,促进了氧化膜的破裂。
The effects of hydrostatic pressure on the electrochemical corrosion behavior of X100 pipeline steel in 0.5 mol / L Na + HCO3 + 0.03 mol / L NaCl solution were investigated by potentiodynamic polarization, electrochemical impedance spectroscopy and electrochemical impedance spectroscopy (Mott-Schottky) . The results show that with the increase of hydrostatic pressure, the number and area of pits on the surface of X100 steel increases. The increase of hydrostatic pressure increases the activity of the solution ions and promotes the adsorption of Cl- in the passivation film. The corrosion reaction rate increases and the corrosion current density increases . Hydrostatic pressure increases the passivation film composition from low-pressure oxide or hydroxide into high-pressure carbonate, resulting in reduced corrosion resistance, and pitting nucleation rate increased. X100 pipeline steel passivation film with n-type semiconductor properties, with hydrostatic pressure increases, the passivation film Cl- increased lattice defects, and promote the rupture of the oxide film.