摘要
目的灰口铸铁给水管道运行过程必然造成内壁发生不同程度的腐蚀,通过实验研究内腐蚀各影响因素,分析灰口铸铁供水管道腐蚀变化规律.方法在调查分析埋地供水管道腐蚀状况及腐蚀原因的基础上,对灰口铸铁试片进行室内挂片实验,分别考虑不同溶解氧、pH值、余氯和流速的条件下的腐蚀速率.同时对灰口铸铁管的内壁腐蚀产物进行电子扫描电镜分析和X-射线衍射分析,确定内壁腐蚀结构成分.结果pH<5和pH>11时腐蚀速率分别呈线性递增和线性递减趋势,水中溶解氧在初始50h内消耗速度呈直线增加变化,随后DO消耗速度几乎不变,余氯对腐蚀过程有促进作用,流速与铸铁管道的腐蚀速率成正比例关系.结论pH值、溶解氧、余氯、流速和侵蚀性CO2是引起灰口铸铁供水管道内腐蚀的主要原因.
Internal corrosion will occur to some different degree with the operation of grey cast iron water supply pipelines. The purpose of this article is to analyze the grey cast iron pipe＇s corrosion rules in water distribution system by experimental study on influencing factors of internal corrosion. On the basis of investigating the current corrosion situation and corrosion causes of buried metallic pipe in water distribution, this experiment is taken in-house laboratory, and analyzes the corrosion rate under conditions of different dissolved oxygen,pH, chlorine residual and flow velocity. The corrosion products components are determined by SEM and XRD analysis. The results of the experiment are that dissolved oxygen, pH, chlorine residual and flow velocity can influence the corrosion rate sharply. Corrosion rate will linearly increase or decrease respectively with pH 〈 5 and pH 〉 11. The value of dissolved oxygen in water will linearly increase in incipient fifty hours, then keep steady. Chlorine residual promotes corrosion rate. Flow velocity is directly proportional to corrosion rate. These internal corrosion influencing factors are the main causes of grey cast iron pipeline corrosion in water distribution.
出处
《沈阳建筑大学学报（自然科学版）》
CAS
北大核心
2010年第2期321-325,共5页
Journal of Shenyang Jianzhu University：Natural Science
基金
国家科技支撑计划项目(2006BAJ06B07)
关键词
供水管道
内壁腐蚀
腐蚀因素
灰口铸铁
water supplying pipe
internal corrosion
corrosion factors
grey cast iron
