摘要
由于实际供水管道的流动情况难以模拟,目前关于流速对球墨铸铁管道腐蚀影响的系统研究较少。将电化学测试装置和循环管路相结合,引入水质更新系统,建立了流动腐蚀模拟监测系统。以球墨铸铁供水管道为研究对象,通过线性极化电阻、电化学阻抗谱和极化曲线测试,揭示了流速对球墨铸铁腐蚀速率、腐蚀垢层结构和阴阳极反应过程的影响规律。结果表明:球墨铸铁在自来水腐蚀环境下,经历了初始期、发展期和稳定期3个腐蚀阶段;流速增大能够加速氧的阴极去极化过程,但也间接促进了垢层生长,与腐蚀速率基本呈正相关关系;流速增大对阳极反应影响有限,主要促进了阴极反应;不同流速下球墨铸铁腐蚀垢层的物相分析结果表明,α-FeOOH,γ-FeOOH和Fe_3O_4是3种主要的腐蚀产物晶体结构,随着流速的增大,FeCO_3和Fe_3O_4可逐渐转化成稳定性更强的α-FeOOH。
The flow corrosion simulating and monitoring system was established through combining the electrochemical testing device, circulat- ing pipeline and water quality update system. Ductile iron was selected as the research object, and the linear polarization resistance （LPR） , electrochemical impedance spectroscopy （EIS） and polarization curves were employed to evaluate the effects of water flow velocity on the corro- sion rate, corrosion scale layer structure and cathode/anode reaction process. Results showed that the corrosion experience of ductile iron in tap water was divided into the initial stage, the developmental stage and the stable stage. The increase of velocity accelerated the process of cathodic depolarization of oxygen, but also indirectly promoted the growth of scales, which was basically positive correlation with the corrosion rate. The effect of flow velocity on anodic reaction was limited, but the cathodic reaction was greatly promoted. The phase analysis of corrosion scales on ductile iron presented that α-FeOOH, γ-FeOOH and Fe304 were the three kinds of predominant products, and with the increase of flow velocity, FeCO3 and Fe3O4 could gradually transform into more stable α-FeOOH.
作者
郭浩
李雪
刘星飞
尹建华
吕鹏
GUO Hao1,2, LI Xue1 , LIU Xing-fei2, YIN Jian-hua1,3, LYU Peng4(1. The Institute of Seawater Desalination and Multipurpose Utilization, SOA（Tianjin）, Tianjin 300182 , China; 2. School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China; 3. Tianjin Zhonghai Water Treatment Technology Co., Ltd., Tianjin 300192, China; 4. Tianjin SDIC Jinneng Electric Power Co., Ltd., Tianjin 300480, China)
出处
《材料保护》
CAS
CSCD
北大核心
2018年第9期40-44,93,共6页
Materials Protection
基金
国家自然科学基金项目(51278333)
中央级公益性科研院所基本科研业务费专项资金项目(K-JBYWF-2016-T5)
中央级公益性科研院所基本科研业务费专项资金项目(K-JBYWF-2016-T4)资助
关键词
流速
球墨铸铁供水管道
腐蚀机理
电化学阻抗谱
极化曲线
water flow velocity
ductile iron pipes
corrosion mechanism
electrochemical impedance spectroscopy
polarization curves
