中文摘要：

通过电化学阻抗谱、极化曲线与失重测量，研究了直流杂散电流对接地网材料Q235扁钢、Q235镀锌扁钢和Cu在含水率分别为15％和20mass％的土壤中腐蚀特性的影响。结果表明：在含水率为15％的土壤中无论是否加载杂散电流，接地网材料EIS谱的扩散阻抗除Q235镀锌扁钢外均表现为与45°角相近的斜线段，在含水率为20％的土壤中，所有的EIS谱都表现为具有两个时间常数的双容抗弧。随含水率的增加，接地网材料的容抗弧明显缩小，腐蚀电流密度和失重速率明显增大；在含水率相同的土壤中，有直流杂散电流干扰时，接地网材料的容抗弧比无干扰时要小，而腐蚀电流密度和失重速率明显增大；3种接地网材料的耐蚀性排序是：Cu最好，Q235镀锌扁钢次之，Q235扁钢最差。

英文摘要：

The influence of DC stray current on corrosion behavior of grounding grid materials, Q235 flat steel,Q235 galvanized flat steel, copper in soil with 15% or 20% moisture content was investigated by means of electrochemical impedance spectroscopy（EIS）, polarization curve technique and mass loss measurement. Results showed that in soil with 15% moisture content diffusion impedance of grounding grid materials showed a similar diagonal section with a 45~ angle except Q235 galvanized flat steel, while all the EIS presented double capacitive loops with two time constants. Capacitive loop of three kinds of grounding grid materials were shrinked with 20% moisture content, meanwhile corrosion current density and mass loss rate were increased. In soil with the same moisture content, the capacitive loop of grounding grid materials were smaller with DC stray current rather than none, meanwhile the corrosion current density and weight-loss rate were increased. The corrosion resistance of the test materials may be ranked that copper is thebest, Q235 galvanized flat steel is the second, Q235 fiat steel is the worst.