紫铜T2和黄铜H62在热带海洋大气环境中早期腐蚀行为

INITIAL CORROSION BEHAVIOR OF COPPER AND BRASS IN TROPICAL MARITIME ATMOSPHERIC ENVIRONMENT

通过现场暴露实验,研究了紫铜T2和黄铜H62在西沙群岛典型热带海洋大气环境中暴露1、3、6个月后的腐蚀行为。采用扫描电镜观察腐蚀产物的表面和断面微观形貌,并用能量色散谱(EDS)和X射线衍射仪(XRD)分析了腐蚀产物元素和组成。测试紫铜T2和黄铜H62电化学阻抗谱(EIS)。结果表明,紫铜T2和黄铜H62在西沙海洋大气环境中暴露早期均发生了明显的局部腐蚀,O和Cl^-是促进早期腐蚀的主要原因,高的相对湿度、温度、Cl^-含量和长日照以及砂石粉尘对铜及铜合金的腐蚀起到加速作用。紫铜T2的主要腐蚀产物为Cu_2O,黄铜H62的主要腐蚀产物为Cu_3Cl_4(OH)_2和Zn_5(OH)_8Cl_2·H_2O。

The corrosion behavior and regularity of copper T2 and brass H62 exposed in tropical maritime atmospheric environment in Xisha Islands for 1 month,3 mouths and 6 months were studied through field exposure test.The surface and cross-sections morphologies of corrosion products were observed using SEM, energy dispersive spectromet（EDS） and X-ray diffraction（XRD） analysis were used to obtain the detailed information of the corrosion products.Electrochemical impedance spectroscopy（EIS）measurements were made for copper T2 and brass H62 specimens.The results showed that obvious localized corrosion occurred for copper T2 and brass H62 specimens in maritime atmospheric environment in Xisha Islands.The existence of O and Cl^- is the main reason for the initial corrosion.The relatively high relativity humidity,temperature,Cl^- amount, long sunshine,and the existence of dust accelerated the corrosion of copper T2 and brass H62 specimens.The main corrosion product for copper T2 is Cu_2O and for brass H62 are Cu_3Cl_4（OH）_2 and Zn_5（OH）_8Cl_2·H_2O.