除铜剂中Cl^-对钢铁零件的腐蚀分析

Corrosion Analysis of Chlorion in Decoppering Agent for Iron and Steel Parts

通过除铜腐蚀对比试验和对除铜剂各成分作用的分析证明，用铬酐一铵盐体系的除铜剂处理钢铁零件时，当含有一定量Cl-时钢铁表面会发生电化学腐蚀，腐蚀特征为点状腐蚀，腐蚀表面呈不均匀分布密集斑点。除铜剂中Cl-诱发腐蚀的原因与其浓度和界面的氧浓差相关，配制除铜剂时应注意防止Cl-的带入，浸泡零件时应定时翻动零件或搅动溶液。

The comparison test of decoppering corrosion was conducted and the theoretical analysis of decoppering agent composition was carried out. Results showed that when iron and steel parts were treated with decoppering agent of chromic anhydride-ammonium salt system, the electrochemical corrosion would occur on iron and steel surface due to the existence of a certain amount of C1-. The corrosion feature was tubercular corrosion and non-uniform distribution of close spots on corrosion surface. The corrosion reason caused by C1- in decoppering agent was related to its concentration and oxygen concentration difference at the interface. It was suggested that C1- should be avoided during compounding decoppering agent and the solution needed to be stirred regularly during immersing parts.