Corrosion rate and scale of cast iron in water distribution systems
Corrosion rate and scale of cast iron in water distribution systems
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DOI：
10.1007/s12209-016-2923-4
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发表时间：
2016-12
影响因子：
7.1
通讯作者：
Hao Guo;Yi-mei Tian;Haolin Chen;Yufen Fu;Xingfei Liu
中科院分区：
文献类型：
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作者：
Hao Guo;Yi-mei Tian;Haolin Chen;Yufen Fu;Xingfei Liu
一个专门的电化学测量单元被插入到一个试验配水系统中，以模拟管道内壁的腐蚀。利用线性极化电阻(LPR)技术和电化学阻抗谱(EIS)实时测量了铸铁的腐蚀速率(CR)和氧化皮的变化。LPR分析表明，腐蚀分为3个阶段：初期CR波动大，发展阶段CR缓慢下降，稳定阶段CR低，约为0.157 5 mm·a-1。交流阻抗谱表明，在稳定阶段形成了外层致密、内层疏松的氧化膜，极化电阻约为2175Ω·cm2。结垢的物理化学分析表明，氧化铁、氢氧化物和方解石使结垢外层致密，有效地限制了氧在结垢中的扩散，导致了较低的CR。
A specialised electrochemical measurement cell was plugged into a pilot water distribution system to simulate the pipe inner-wall corrosion. The linear polarisation resistance (LPR) technique and electrochemical impedance spectroscopy (EIS) were measured in real time to study the variation of the corrosion rate (CR) and scale of cast iron. Three corrosion stages were observed according to the LPR analysis: an initial stage with significantly fluctuating CR, a developmental stage with slowly decreasing CR, and a stable stage with a low CR of approximately 0.157 5 mm·a-1. The EIS revealed that the scales with a compact outer layer and a porous inner layer finally formed in the stable stage, and the polarisation resistance was approximately 2 175 Ω·cm2. A physicochemical analysis of the scales showed that ferric oxides, oxyhydroxides and calcite made the outer layer compact and effectively limited the diffusion of oxygen through the scales, which resulted in a low CR.