不同破损程度下车辆镀锌钢板腐蚀行为研究

Corrosion Behavior of Vehicle Zinc Coating Steel Sheet with Different Breakage Degree

采用自腐蚀电位、电化学阻抗谱和极化曲线技术，研究了不同破损程度下车辆镀锌钢板在3．5％NaCl溶液中的腐蚀行为。研究结果表明：完好镀锌钢板的自腐蚀电位最低，随着破损程度增大，自腐蚀电位逐渐升高；破损镀锌钢板的腐蚀电流密度均高于基板，电偶效应使镀锌层对基体金属的腐蚀防护起了重要作用。

The corrosion behavior of zinc coating with different breakage degree was studied by the technology of free corro- sion potential, electrochemical impedance spectroscopy and potential-dynamic polarization in 3.5% NaC1 solution. The re- sults show that the free corrosion potential of intact zinc coating is lower than damaged zinc coating, and the open circuit po- tential increase gradually with the increase of breakage degree. The corrosion current density of damaged zinc coating is higher than substrate and the zinc coating plays an important role in the protection of the damaged sample substrate against COrrosion.