紫铜在云南热带雨林土壤中的长期腐蚀行为

Long Term Corrosion Behavior of Copper in Yunnan Tropical Rainforest Soil

采用失重法、形貌分析、成分分析和电化学测试等方法研究了紫铜管长期埋藏于热带雨林土壤环境中的腐蚀行为。结果表明,紫铜管埋藏16 a的平均腐蚀速率为2.5μm/a,腐蚀失重规律符合幂函数模型,其拟合方程为C=0.4273t−0.246。紫铜管表面腐蚀产物呈淡绿色的致密鳞状结构,与金属基体结合良好。XPS、EDS、FTIR和XRD分析结果显示该腐蚀产物主要成分为铜绿(Cu2(OH)2CO3)、Cu2O和CuO。电化学测试结果表明,埋藏16 a后,紫铜管腐蚀速率变小,阻抗值明显增大,表明腐蚀产物膜对基体形成良好的保护作用,能有效减缓腐蚀过程的继续发展。

The corrosion behavior of copper pipes buried in tropical rainforest soil environment for a long time was studied by mass-loss method,morphology analysis,composition analysis and electrochemical test.The results show that average corrosion rate is 2.5μm/a for copper pipes buried in soil for 16 a,he law of corrosion mass loss conforms to the power function model,and its fitting equation is C=0.4273t−0.246.The corrosion products on the surface of the copper pipe exhibit a light-green dense scale structure,which is well combined with the metal matrix.XPS,EDS,FTIR and XRD analysis results show that the main component of the corrosion products are copper green(Cu2(OH)2CO3),Cu2O and CuO.The electrical test results show that after 16 a of burial,the corrosion rate of the copper pipe decreases and the impedance value increases significantly,indicating that the corrosion product film has a good protective effect on the substrate and can effectively retard the corrosion.