采用灰色关联度方法, 分析了土壤中常见阴离子及pH对紫铜和热镀锌钢在土壤浸出液中腐蚀速率影响程度的大小, 得到了对腐蚀速率影响最大的显著因子。通过开路电位测量、EIS分析和极化曲线测量研究了显著因子对材料的腐蚀影响。结果表明,Cl-和pH是影响紫铜和热镀锌钢腐蚀速率的显著因子,Cl-摩尔浓度为0.01 mol/L和0.1 mol/L时, Cl-主要通过改变紫铜表面荷电状态影响腐蚀速率大小;当其摩尔浓度为0.3 mol/L时, Cl-降低了紫铜电极反应电荷传递阻力, 使腐蚀加速, 此时pH对紫铜腐蚀的影响不再显著。热镀锌钢在含Cl-的酸性, 碱性溶液中都会发生较严重的腐蚀, Cl-可在镀锌层孔隙中累积造成热镀锌钢的点蚀, 在碱性条件下Cl-更容易在镀锌层中富集。

Significant factors which influence the corrosion rates of red copper and hot-dip galvanized steel in soil extract solution were obtained by analyzing the influence degrees of pH and common anions in the soil with grey correlation method. Corrosion mechanism of grounding grid materials corroded by significant factors was studied by open circuit potential measurement, EIS and polarization curve test. The results showed that Cl- and pH were the significant factors influencing the corrosion rates of red copper and hot-dip galvanized steel. When the concentration of Cl- was 0.01mol/L or 0.1 mol/L, the corrosion rate of red copper was influenced by the state of charge on the surface. When the concentration of Cl- was 0.3 mol/L, the charge transfer resistance reduced due to Cl-, the influence degree of pH on red copper was not significant any more. Hot-dip galvanized steel corroded severely in both acidic and alkaline solutions containning Cl-, pitting was caused by the accumulation of Cl- in Zn coating, and Cl- congested easily in coating in alkaline environment.