某集气站排污水管腐蚀失效原因分析

Corrosion Failure Analysis on a Wastewater Pipeline for a Gas Gathering Station

采用SEM、XRD及EDS等对某集气站排污水管失效管段进行宏观检查、腐蚀产物分析和污水水样分析,根据排污水管的工况开展了腐蚀模拟实验。结果表明:污水中存在大量硫酸盐还原菌(SRB)和少量铁细菌和腐生菌(TGB),污水存在明显腐蚀结垢趋势,细菌腐蚀和垢下腐蚀是导致腐蚀穿孔的主要原因,污水中的Cl-加速了腐蚀的发生。

Corrosion failure of a waste water pipeline for a gas gathering station was analyzed by means of corrosion morphology observation, corrosion product analysis by using SEM, XRD and EDS,as well as analysis of wastewater. Experiments were also carried out to simulate the working condition in order to understand the corrosion behavior of waste water pipeline. The results showed that a lot of sulfate reducing bacteria（SRB） and a small amount of saprophytic bacteria（TGB） and iron bacteria were detected in the wastewater, by which the formation scaling on the pipeline might be facilitated. The corrosion failure of the wastewater pipeline was due to the microbiological influenced corrosion（MIC） and underdeposit corrosion. The Cl-in the wastewater accelerated the corrosion process.