NaCl和CO_2对Zn在薄液膜下腐蚀的协同作用

SYNERGISTIC EFFECT OF NaCl AND CO_2 ON ATMOSPHERIC CORROSION OF ZINC UNDER THIN ELECTROLYTE FILM

使用石英晶体微天平（ＱＣＭ：ｑｕａｒｔｚ ｃｒｙｓｔａｌ ｍｉｃｒｏｂａｌａｎｃｅ）为主要手段研究了在 ８５％ＲＨ相对湿度）和 ＮａＣＩ存在的条件下，金属Ｚｎ在不同ＣＯ２浓度下的大气腐蚀动力学，同时结合 Ｘ射线衍射（ＸＲＤ）和扫描电镜（ＳＥＭ）研究了Ｚｎ在薄液膜下的大气腐蚀机理，并用扫描电子显微＃（ＳＥＭ）对腐蚀产物进行形貌分析，阐述了腐蚀产物的保护特征．实验结果表明，在薄液膜下，ＮａＣｌ的存在使金属Ｚｎ表面生成一层具有良好保护性的膜，对Ｚｎ的 ＣＯ２大气腐蚀具有缓蚀作用，所以，ＮａＣｌ和ＣＯ２的相互作用对 Ｚｎ的大气腐蚀具有协同效应．

Quartz crystal microbalance has been used to study the kinetics on atmospheric corrosiori of zinc in air containing different concentrations of carbon dioxide. Combined with x-ray diffraction and scanning electron microscopy, the corrosion mechanisms for zinc under thin electrolyte film was discussed. The measured results by quartz crystal microbalance show that carbon dioxide can slOW down the corrosion rate of zinc in the presence of NaCl. This is explained by the neutralization of safe electrolyte resulting in the precipitation of chloride in the form of insoluble Zn5(OH)8Cl2.H2O. It is called as synergistic effect of NaCl and CO2 on atmospheric corrosion of zinc under thin electrolyte film. Protective features is elucidated by analysis on morphology of atmospheric corrosion layer on zinc using SEM.