The influence of groundwater anions on the impedance behaviour of carbon steel corroding under anoxic conditions
The influence of groundwater anions on the impedance behaviour of carbon steel corroding under anoxic conditions
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DOI：
10.1016/j.electacta.2005.02.115
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发表时间：
2006-01
影响因子：
6.6
通讯作者：
C. T. Lee;Z. Qin;M. Odziemkowski;D. Shoesmith
中科院分区：
文献类型：
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作者：
C. T. Lee;Z. Qin;M. Odziemkowski;D. Shoesmith
在铜核废料容器内，碳钢衬垫产生Fe2+和H2O2的缺氧腐蚀可导致驱动核燃料（UO2）腐蚀所需的放射性氧化剂（H2O2, O2）的清除和放射性核素的释放。在不同浓度的Na2CO3/NaHCO3、na2so4和NaCl溶液中研究了钢的腐蚀，以模拟地下水成分随时间从碳酸盐为主到氯化物为主的预期变化。电化学技术、扫描电子显微镜和原位拉曼光谱的结合已经被使用。在浓碳酸盐溶液中，通过HCO3 -络合Fe2+和HCO3 -解离提供的质子的减少，腐蚀维持在铁铁矿（FeCO3·H2O）沉积物的孔隙内。在较低CO32−/HCO3−浓度的混合阴离子溶液中，表面覆盖一层致密的绿色锈层，腐蚀速率受到抑制。在浓NaCl溶液中，缺乏CO32−/HCO3−缓冲会导致腐蚀过程迅速停止，如果有微量的溶解o2存在，则会形成feii表面相。
The anoxic corrosion of carbon steel liners to produce Fe2+and H2within copper nuclear waste containers could lead to the scavenging of the radiolytic oxidants (H2O2, O2) required to drive nuclear fuel (UO2) corrosion and the release of radionuclides. Steel corrosion has been studied in solutions containing various concentrations of Na2CO3/NaHCO3, Na2SO4and NaCl to simulate an anticipated change in environment from carbonate-dominated to chloride-dominated groundwater composition over time. A combination of electrochemical techniques, scanning electron microscopy, and in situ Raman spectroscopy has been used. In concentrated carbonate solutions, corrosion is maintained within pores in a siderite (FeCO3·H2O) deposit by the complexation of Fe2+by HCO3−and the reduction of protons supplied by HCO3−dissociation. In mixed-anion solutions at lower CO32−/HCO3−concentrations, a compact green rust deposit covers the surface and the corrosion rate is suppressed. In concentrated NaCl solutions, the absence of CO32−/HCO3−buffering leads to a rapid shut down of the corrosion process which may be aided by the formation of FeIIIsurface phases if traces of dissolved O2are available.