交流干扰下管道最佳保护准则探究

为了探究交流干扰下抑制管道发生腐蚀的最佳保护准则,通过试验确定交流干扰下达到最佳保护状态时的阴极保护电位,首先验证经典的-0.85 Vvs饱和硫酸铜参比电极(CSE)]阴极保护电位准则和负向偏移100mV阴极保护准则在交流干扰下是否还具有良好的保护效果;接着探究阴极保护电位对保护效果的影响,确定保护效果较好时保护电位的范围.在此基础上,再结合保护程度和保护效率2个评价指标全面分析,找出最佳保护状态下的阴极保护电位取值.结果表明:存在交流干扰时,经典的-0.85 V(vs CSE)阴极保护电位准则和负向偏移100 mV阴极保护准则已经失效;在-1.20 V(vs CSE)以内,阴极保护电位负向升高,对交流干扰下的腐蚀抑制作用会增强;综合腐蚀速率、保护程度和保护效率3个因素,得到交流电流密度在50 A/m2以内时,建议采用-1.00 V(vs CSE)的保护电位;交流电流密度大于50A/m2时,建议采用-1.10 V(vs CSE)的保护电位.

Research on the Best Protection Criterion of Pipeline Under AC Interference

In order to study the optimum protective criteria to inhibit pipeline corrosion under alternating current (AC) interference,experiments were established to determine the protective potential under optimum protection conditions in this paper.Firstly,both the criteria of classic-0.85 V (vs CSE) cathodic protective potential and negative offset 100 mV cathodic protective potential were verified under AC interference.Then,the influence of the cathodic protective potential on protection effect was studied to determine the protective potential range under preferable effect.Based on this,combined with the overall analysis on the two evaluation indicators of protective degree and protective efficiency,the cathodic protective potential was obtained under the optimum protective conditions.Results showed that,when AC interference existed,the criteria of classic-0.85 V (vs CSE) cathodic protective potential and negative offset 100 mV cathodic protective potential both failed;within -1.20 V(vs CSE),the protective potential increased negatively and consequently the effect of corrosion inhibition would be enhanced under AC interference.Comprehensively considered the three factors of corrosion rate,protective degree and protective efficiency,the protective potential of-1.00 V(vs CSE) was suggested to adopt when the alternating current density was within 50 A/m2;whereas the protective potential of-1.10 V(vs CSE) was suggested to adopt when the alternating current density was above 50 A/m2.