浅谈3PE钢管防腐层剥离的主要机理
The Main Mechanism of Coating Disbondment for 3PE Pipes

管道外防腐涂敷过程中热膨胀失配产生的残余应力是防腐层剥离的内在影响因素；防腐层性能的好坏决定了防腐层抗阴极剥离的能力，防腐层自身缺陷多、阴极保护电位过大将加剧防腐层阴极剥离的速度；水和氧气等侵蚀性离子的渗透是造成最终防腐层剥离的先决条件；现场施工质量特别是施工作业人员技术水平低下也是客观造成管道防腐层及早失效的关键因素；优化3PE管道防腐层涂敷工艺及质量控制水平有助于提高防腐层耐剥离能力。
The residual stress caused by thermal expansion mismatch is the internal and main factor for the disbondment of the 3PE coating; the performance of the 3PE layer determines its anti-disbondment capability. The 3PE layer which has many defects and the over cathodic protection potential also will cause and exacerbate the disbondment. Penetration of aggressive ions such as water and oxygen is a prerequisite for the 3PE layer stripping; the quality of the site construction, especially the low quality of construction workers, is also a key factor that causes the pipeline 3PE layer to fail early; optimizing 3PE layer coating process and quality control level would help to improve its anti-disbondment capability.