西部地区高强钢管道三层聚乙烯防腐蚀层的剥离性能

Stripping Quality of Three Layer Polyethylene Coating on High Strength Steel Pipeline in Western Region

对西部某高强钢管道三层聚乙烯(3PE)防腐蚀层进行了现场调查,同时采用扫描电子显微镜(SEM)观察、能谱(EDS)分析、截面厚度测试等手段对典型剥离位置熔结环氧(FBE)表面进行了分析,探究了防腐蚀层失效的原因。结果表明:现场检测发现的3处防腐蚀层剥离,其中2处与防腐蚀层制备过程的控制参数相关,环氧粉末固化度不满足要求是导致剥离的主要原因,涂层的厚度和表面清洁度控制也存在一定的问题;另外1处失效与施工造成的机械损伤有关,损伤位置附近涂层在阴极保护的作用下发生剥离。

A field investigation was conducted on the anti corrosion layer of a three-layer polyethylene （3PE） on a high strength steel pipeline in the west. At the same time, scanning electron microscopy （SEM） observation, energy spectrum （EDS） analysis, cross-section thickness test and other methods were used to analyze the surface of the fusion bonded epoxy （FBE） at typical exfoliation positions, and the reasons for the failure of the anti corrosion layer were explored. The results showed that the anti-corrosion layers found on site at3 positions were stripped, and two of them were related to the control parameters of the anti-corrosion layer preparation process. The main cause of peeling was that the epoxy powder curing degree didn＇t meet the requirement. The coating thickness and surface cleanliness control also had certain problems. In addition, one failure was related to the mechanical damage caused by construction. The coating near the damage site was peeled off under the action of cathodic protection.