在不同的充氢电流密度和充氢时间下对X80钢进行电化学充氢.测量了不同充氢条件下X80钢在鹰潭土壤模拟溶液中的极化电阻和腐蚀速率.结果表明,随着充氢电流密度由1 mA/cm2增加至20 mA/cm2,X80钢的自腐蚀电位负移,电荷转移电阻Rt由1 176 Ω·cm2降至909 Ω·cm2,双电层电容由0.000 16 μF/cm2增加至0.001 7 μF/cm2,腐蚀电流密度从3.322mA/cm2增加至6.880 mA/cm2.当充氢时间由1h增加至5h,电荷转移电阻Rt由1 522 Ω·cm2降至749 Ω·cm2,双电层电容由0.000 14μF/cm2增加至0.00 75μF/cm2,腐蚀电流密度从2.91 mA/cm2增加至5.01 mA/cm2.以上表明,电化学充氢使X80钢表面的薄弱点的阳极溶解率和金属离子的浓度高增加.氢加速阳极溶解,最终的结果是发生较高的腐蚀敏感性.%X80 pipeline steel specimens were treated by electrochemical hydrogen charging under various current densities and charging time. The polarization resistance and corrosion rate of X80 steel were analyzed in Yingtan simulated soil solution under the different hydrogen charging conditions. The results show that with the hydrogen charging current density increased from 1 mA/cm2 to 20 mA/cm2, the free-corrosion potential of X80 moved negatively, charge transfer resistance R1 dropped from 1 176 Ω · cm2 to 909 Ω · cm2, double electric layer capacitors increased from 0. 000 16 μF/cm2 to 0. 001 7 μF/cm2 and corrosion current density increased from 3. 322 mA/cm2 to 6. 880 mA/cm2. When filling hydrogen time increased from 1 h to 5 h, Rt changed from 1 522 Ω · cm2 down to 749 Ω · cm2, double electric layer capacitors increased from 0. 000 14 μF/cm2 to 0. 007 5 μF/cm2 and corrosion current density increased from 2. 91 mA/cm2 to 5. 01 mA/cm2. This suggests that electrochemical hydrogen charging result in anodic dissolution rate of the weak spots and concentration of metal ions increased. Hydrogen speeded up anodic dissolution of X80 steel and leaded to higher corrosion sensitivity at the steel surface.
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