模拟宫腔液中铜腐蚀行为的研究

AN INVESTIGATION ON CORROSION BEHAVIOUR OF COPPER IN SIMULATED UTERIUE FLUID

铜在模拟宫腔液中腐蚀后，溶液分析和表面膜阴极还原都证明，以离子形态进入溶液的铜在腐蚀总量中所占的比例随溶液ｐＨ而不同。ｐＨ７时约占三分之一。当ｐＨ降低，这个比例明显增大。模拟宫腔液中溶解氧对铜腐蚀的影响，由于促进溶解和有利成膜的两个相反的作用，在某个氧分压下腐蚀速度出现极大值，ｐＨ７和ｐＨ８时分别为０．１２ａｔｍ和０．０６ａｔｍ。根据铜的自然腐蚀电位随介质ｐＨ的变化，应用Ｃｕ－Ｃｌ－Ｈ２Ｏ的电位－ｐＨ图解释了这一腐蚀过程。

Corrosion behaviour of copper in simulated uterine fluid was investigated by electrochemical and chemical means. Both cathodic reduction of surface film and chemical analysis of solution after corrosion testing proved that the percentage of ionic copper in the corrosion products varied with the pH level of the fluid. About one-third of the total amount of the corroded copper was soluble at pH 7. The share of the soluble products increassed significantly with decreasing pH. In order to examine the effect of oxygen dissolved in the test fluid, the instantaneous corrosion rates under different oxygen pressures were determined using polarization resistance method. A maximum of corrosion rate was observed at a certain oxygen pressure. They were 0.12 atm for pH 7 and 0.06 atm for pH 8, respectively. Based on the variation of the natural corrosion potential of copper with environmentlal pH, the corrosion process was interpreted using E-pH diagram for Cu-Cl-H2O system.