Q235钢/NaCl液滴界面微区电化学特征参数分布特征

Characteristics of Micro-areal Distribution of Elecrochemical Parameters on Q235 Steel under NaCl Electrolyte Droplet

本文采用扫描Kelvin探针、扫描振动电极等方法表征了NaCl液滴覆盖下Q235钢表面的微区电化学参数分布的特征.结果证实,NaCl液滴下碳钢表面的电位分布和电流密度分布是不均匀的,中心为阳极区,边缘为阴极区.液滴中心和边缘阴阳极电位相差0.4 V,阴阳极电流密度相差0.9μA/cm2.NaCl液滴下碳钢表面电化学参数的不均匀分布导致液滴边缘发生强烈的阴极极化,导致附近区域碱性化是微液滴形成的主要原因.

Characteristics of micro-areal distribution of electrochemical parameters on Q235 steel under NaCl electrolyte droplet was studied by using scanning Kelvin probe and scanning vibrating electrode technique.Results show that the electric current density and potential distribution of carbon steel under NaCl droplet is asymmetrical,area under the fringe of the droplet is cathode,while that under the center is anode.Potential difference between the anode and the cathode is 0.4 V and current density difference is 0.9 μA/cm2.This kind of asymmetrical distribution of electrochemical characteristics results in cathodic polarization in the fringe of NaCl dropletand and then introduction of OH-,therefore it is the reason for the formation of micro-electrolyte droplets.