本powerpoint演示文稿调查 球墨铸铁的腐蚀机理 带聚乙烯外壳的管道（DIP） （PE）根据AWWA C105 标准方法包括: 模拟DIP和PE之间的小间隙 表面和水分被截留的地方； 3种浸渍条件下的PE试验； 退火氧化物涂层； 去除退火氧化物涂层（裸）； 沥青涂层（生产时）；和 取样并进行化学分析 流体是时间的函数。陈述结论表明: 沥青层下陷几乎没有迹象表明 腐蚀 保护性沥青涂层防止接触 在腐蚀性孔隙流体和倾角之间，以及 未检测到半挥发性有机物；退火氧化层浸渍作为一种 保护层和 顶部的点蚀环 由更大的 溶解氧；裸泳 没有保护层 顶部环附近的点蚀和 均匀腐蚀 下部；腐蚀机理是 强烈地受到溶解气体的影响 氧气 PE剥夺了系统的氧气 溶解氧增加腐蚀； pH值随着腐蚀的进行而增加； LPR读数表明一般腐蚀；和 半挥发性有机物 这不是腐蚀控制的一个因素。包括表格、数字。

This powerpoint presentation investigates the mechanism(s) of corrosion on ductile iron pipe (DIP) with polyethylene encasement (PE) in accordance with AWWA C105 standard. Methodology included the following: simulate small gap between DIP and PE surface and where moisture is trapped; PE test of 3 DIP conditions; annealing oxide coating; removed annealing oxide coating (Bare); asphaltic coating (as manufactured); and, sample and chemically analyze trapped fluid as a function of time. Presentation conclusions indicate that: asphaltic DIP showed little to no signs of corrosion, protective asphaltic coating prevents contact between corrosive pore fluid and DIP, and no semi-volatile organics were detected; annealing oxide DIP acts as a protective layer and pitting rings at top caused by greater dissolved oxygen; bare DIP offered no protective layer with pitting near top rings and uniform corrosion at lower portion; corrosion mechanism is strongly influenced by dissolved oxygen, PE deprives system of oxygen, and dissolved oxygen increases corrosion; pH increases as corrosion proceeds; LPR readings indicate general corrosion; and, semi-volatile organics are not a factor in corrosion control. Includes tables, figures.